Online Etymology Dictionary

squadron (n.): 1560s, from Italian squadrone, augmentative of squadra "battalion," literally "square" (see squad). As a division of a fleet, from 1580s, of an air force, 1912.
squalid (adj.): 1590s, from Middle French squalide and directly from Latin squalidus "rough, coated with dirt, filthy," related to squales "filth," squalus "filthy," squalare "be covered with a rough, stiff layer, be coated with dirt, be filthy," of uncertain origin. Related: Squalidly; squalidness; squalidity.
squall (n.): "sudden, violent gust of wind," 1719, originally nautical, probably from a Scandinavian source (compare Norwegian skval "sudden rush of water," Swedish skvala "to gush, pour down"), probably ultimately a derivative of squall (v.).
squall (v.): "cry out loudly," 1630s, probably from a Scandinavian source, such as Old Norse skvala "to cry out," and of imitative origin (compare squeal (v.)). Related: Squalled; squalling. As a noun from 1709.
squally (adj.): 1719, from squall + -y (2).
squalor (n.): 1620s, "state or condition of being miserable and dirty," from Latin squalor "roughness, dirtiness, filthiness," from squalere "be filthy" (see squalid).
squamous (adj.): 1540s, from Latin squamosus "covered with scales, scaly," from squama "scale," perhaps related to squalus "foul, filthy" (see squalid). Middle English had squame "a scale" (late 14c.), from Old French esquame, from Latin squama. Alternative form squamose attested from 1660s.
squander (v.): 1580s (implied in squandering), "to spend recklessly or prodigiously," of unknown origin; Shakespeare used it in "Merchant of Venice" (1593) with a sense of "to be scattered over a wide area." Squander-bug, a British symbol of reckless extravagance and waste during war-time shortages, represented as a devilish insect, was introduced 1943. In U.S., Louis Ludlow coined squanderlust (1935) for the tendency of government bureaucracies to spend much money.
square (n.): mid-13c., "tool for measuring right angles, carpenter's square," from Old French esquire "a square, squareness," from Vulgar Latin *exquadra, back-formation from *exquadrare "to square," from Latin ex- "out" (see ex-) + quadrare "make square, set in order, complete," from quadrus "a square" (see quadrant).

Meaning "square shape or area" is recorded by late 14c. (Old English used feower-scyte). Geometric sense "four-sided rectilinear figure" is from 1550s; mathematical sense of "a number multiplied by itself" is first recorded 1550s. Sense of "open space in a town or park" is from 1680s; that of "area bounded by four streets in a city" is from c. 1700. As short for square meal, from 1882. Square one "the very beginning" (often what one must go back to) is from 1960, probably a figure from board games.
square (adj.): early 14c., "containing four equal sides and right angles," from square (n.), or from Old French esquarre, past participle of esquarrer. Meaning "honest, fair," is first attested 1560s; that of "straight, direct" is from 1804. Of meals, from 1868.

Sense of "old-fashioned" is 1944, U.S. jazz slang, said to be from shape of a conductor's hand gestures in a regular four-beat rhythm. Square-toes meant nearly the same thing late 18c.: "precise, formal, old-fashioned person," from the style of men's shoes worn early 18c. and then fallen from fashion. Squaresville is attested from 1956. Square dance attested by 1831; originally one in which the couples faced inward from four sides; later of country dances generally.
[T]he old square dance is an abortive attempt at conversation while engaged in walking certain mathematical figures over a limited area. ["The Mask," March 1868]
square (v.): late 14c. of stones, from Old French esquarrer, escarrer "to cut square," from Vulgar Latin *exquadrare (see square (adj.)). Meaning "regulate according to standard" is from 1530s; sense of "to accord with" is from 1590s. With reference to accounts from 1815. In 15c.-17c. the verb also could mean "to deviate, vary, digress, fall out of order." Related: Squared; squaring.
square (adv.): 1570s, "fairly, honestly," from square (adj.). From 1630s as "directly, in line." Sense of "completely" is American-English, colloquial, by 1862.
squared (adj.): late 14c., "made square," past participle adjective from square (v.). Meaning "drawn up in squares" is from 1660s. Of numbers, "multiplied by itself," from 1550s.
squarely (adv.): 1540s, of multiplication, from square (adj.) + -ly (2). From 1560s as "in a straightforward manner;" meaning "firmly, solidly" is from 1860.
squash (v.): "to crush, squeeze," early 14c., squachen, from Old French esquasser, escasser "to crush, shatter, destroy, break," from Vulgar Latin *exquassare, from Latin ex- "out" (see ex-) + quassare "to shatter" (see quash "to crush"). Related: Squashed; squashing.
squash (n.1): gourd fruit, 1640s, shortened borrowing from Narraganset (Algonquian) askutasquash, literally "the things that may be eaten raw," from askut "green, raw, uncooked" + asquash "eaten," in which the -ash is a plural affix (compare succotash).
squash (n.2): 1610s, "act of squashing," from squash (v.). The racket game called by that name 1899; earlier (1886) it was the name of the soft rubber ball used in it.
squashy (adj.): 1690s, from squash (n.2) + -y (2).
squat (v.): mid-14c., "to crush;" early 15c., "crouch on the heels," from Old French esquatir, escatir "compress, press down, lay flat, crush," from es- "out" (see ex-) + Old French quatir "press down, flatten," from Vulgar Latin *coactire "press together, force," from Latin coactus, past participle of cogere "to compel, curdle, collect" (see cogent). Meaning "to settle on land without any title or right" is from 1800. Related: Squatted; squatting.
squat (adj.): early 15c., "crouch on the heels, in a squatting position," from squat (v.)). Sense of "short, thick" dates from 1620s.
squat (n.): c. 1400, "bump, heavy fall," from squat (v.). Meaning "posture of one who squats" is from 1570s; that of "act of squatting" is from 1580s. Slang noun sense of "nothing at all" first attested 1934, probably suggestive of squatting to defecate. Weight-lifting sense is from 1954.
squatter (n.): "settler who occupies land without legal title," 1788, agent noun from squat (v.); in reference to paupers or homeless people in uninhabited buildings, it is recorded from 1880.
squaw (n.): "American Indian woman," 1630s, from Massachuset (Algonquian) squa "woman" (cognate with Narraganset squaws "woman"). "Over the years it has come to have a derogatory sense and is now considered offensive by many Native Americans" [Bright]. Widespread in U.S. place names, sometimes as a translation of a local native word for "woman."
squawk (v.): 1821, probably of imitative origin (compare dialectal Italian squacco "small crested heron"). Related: Squawked; squawking. Squawk-box "loud-speaker" is from 1945.
squawk (n.): 1850, from squawk (v.).
squeak (v.): late 14c., probably of imitative origin, similar to Middle Swedish skväka "to squeak, croak." Related: Squeaked; squeaking.
squeak (n.): 1660s, from squeak (v.); sense of "narrow escape" is by 1811.
squeaky (adj.): 1823, from squeak (n.) + -y (2). Squeaky clean in figurative sense is from 1972, probably from advertisements for dishwashing liquid. Related: Squeakily; squeakiness.
squeal (v.): c. 1300, probably of imitative origin, similar to Old Norse skvala "to cry out" (see squall (v.)). The sense of "inform on another" is first recorded 1865. Related: Squealed; squealing. The noun is attested from 1747.
squeamish (adj.): late 14c., variant (with -ish) of squoymous "disdainful, fastidious" (early 14c.), from Anglo-French escoymous, which is of unknown origin. Related: Squeamishly; squeamishness.
He was somdel squaymous
Of fartyng, and of speche daungerous
[Chaucer, "Miller's Tale," c. 1386]
squeegee (n.): "wooden scraping instrument with a rubber blade," 1844, a nautical word originally, perhaps from squeege "to press" (1782), an alteration of squeeze (v.). Later in photography, then window-washing.
squeezable (adj.): 1813, from squeeze + -able.
squeeze (v.): c. 1600, "press forcibly" (transitive), probably an alteration of quease (c. 1550), from Old English cwysan "to squeeze," of unknown origin, perhaps imitative (compare German quetschen "to squeeze"). Perhaps altered by influence of many words of similar sense in squ-. Intransitive sense from 1680s. Baseball squeeze play first recorded 1905. The 1811 Dictionary of the Vulgar Tongue has squeeze-crab "A sour-looking, shrivelled, diminutive fellow."
squeeze (n.): 1610s, "act of squeezing," from squeeze (v.). Main squeeze "most important person" is attested from 1896; meaning "one's sweetheart, lover" is attested by 1980. Slang expression to put the squeeze on (someone or something) "exert influence on" is from 1711.
squelch (v.): 1620s, "to fall, drop, or stomp (on something soft) with crushing force," possibly imitative of sound made in the process. The figurative sense of "suppress completely" is first recorded 1864. Related: Squelched; squelching.
squib (n.): 1520s, "short bit of sarcastic writing, witty scoff," of unknown origin. If the meaning "small firework that burns with a hissing noise" (also 1520s) is the original one, the word might be imitative.
squid (n.): marine mollusk, cuttlefish, 1610s, of unknown origin; perhaps a sailors' variant of squirt, so called for the "ink" it squirts out.
squiggle (v.): 1804, probably a blend of squirm and wriggle. Related: Squiggled; squiggling.
squiggle (n.): 1902, from squiggle (v.). In reference to handwriting, drawing, etc., 1928. Related: Squiggly (1902).
squinch (v.): 1840 (transitive), of faces; intransitive use from 1843. Perhaps related to squinch "narrow opening in a building" (c. 1600). Also compare squink-eyed (1630s), variant of squint-eyed, so perhaps it is at least partly an altered form of squint. Related: Squinched; squinching.
squint (adj.): 1570s, "looking different ways; looking obliquely," shortened form of asquint (adv.). Meaning "looking indirectly" is from 1610s.
squint (v.): 1590s, from squint (adj.). Related: Squinted; squinting.
squint (n.): "non-coincidence of the optic axes," 1650s, from squint (adj.). Meaning "sidelong glance" is from 1660s.
squire (n.): early 13c., "young man who attends a knight," later "member of the landowning class ranking below a knight" (c. 1300), from Old French esquier "squire," literally "shield carrier" (see esquire). Meaning "country gentleman, landed proprietor" is from 1670s; as a general term of address to a gentleman, it is attested from 1828.
squire (v.): "to attend (a lady) as a gallant," late 14c., from squire (n.). Related: Squired; squiring.
squirm (v.): 1690s, originally referring to eels, of unknown origin; sometimes associated with worm or swarm, but perhaps imitative. Figurative sense "to be painfully affected, to writhe inside" is from 1804. Related: Squirmed; squirming. As a noun from 1839.
squirrel (n.): early 14c., from Anglo-French esquirel, Old French escurueil "squirrel; squirrel fur" (Modern French écureuil), from Vulgar Latin *scuriolus, diminutive of *scurius "squirrel," variant of Latin sciurus, from Greek skiouros "a squirrel," literally "shadow-tailed," from skia "shadow" (see shine (v.)) + oura "tail," from PIE root *ors- "buttocks, backside" (see arse). Perhaps the original notion is "that which makes a shade with its tail." The Old English word was acweorna, which survived into Middle English as aquerne.
squirrel (v.): "to hoard up, store away" (as a squirrel does nuts), 1939, from squirrel (n.). Related: Squirreled; squirreling.
squirrely (adj.): also squirrelly, 1895, "abounding in squirrels;" 1910 as "reminiscent in some way of a squirrel," from squirrel (n.) + -y (2). Earlier was squirrelish (1834). Related: Squirreliness.
squirt (v.): late 15c., squyrten "to spit" (intransitive), of uncertain origin, probably imitative. Transitive sense "cause to issue in a sudden jet or stream" is from 1580s. Related: Squirted; squirting. Squirt-gun attested from 1803.