"having or consisting of curved lines," 1710, from curvi-, combining form of Latin curvus "curved, crooked, bent" (see curve (v.)) + linearis, from linea "line" (see line (n.)). Earlier was curvilineal (1650s).

"state of being curved," 1540s, from Late Latin curvitatem (nominative curvitas), noun of state from past-participle stem of curvare "to bend, curve" (see curve (v.)).

"full of or characterized by curves," 1845, from curve (n.) + -y (2). Related: Curviness.

"bag-like case of cloth, etc., stuffed with soft material and used as a support or for comfort for some part of the body," c. 1300, quishin, from Anglo-French quissyn, Old French coissin "seat cushion" (12c., Modern French coussin), cognate with Medieval Latin cossinus, probably a variant of Vulgar Latin *coxinum, from Latin coxa "hip, thigh," or from Latin culcita "mattress." Someone has counted more than 400 spellings of the plural of this word in Middle English wills and inventories, including quessihon, quoshin, whishin, cuishun, kuchin, koshen. Also from the French word are Italian cuscino, Spanish cojin. Figurative sense of "something to absorb a jolt, shock, etc." is by 1860.

1730s, "to seat on or as on a cushion," from cushion (n.). From 1820 as "furnish with a cushion or cushions." In the figurative sense, "mitigate or absorb the impact of something," by 1863. Related: Cushioned; cushioning.

"easy," 1915, Anglo-Indian slang, from Hindi khush "pleasant, healthy, happy" + -y (2). Wright's "English Dialect Dictionary" (1898) has cush "a soft, useless person," identified as Scottish and Northumberland and explained as "A common term of reproach, used of one who allows others to beat him, either in self-defence or at work," hence cushie "soft, flabby." 

1580s, in astrology, "first entrance of a house in the calculation of a nativity," from Latin cuspis "point, spear, pointed end, head," which is of unknown origin. Astronomical sense is from 1670s, "point or horn of a crescent." Anatomical sense of "a prominence on the crown of a tooth" is from 1839.

"a point," 1743, from Latin cuspis (genitive cuspidis) "point, pointed end," a word of unknown origin. In English from 1640s as cuspis. As "a cuspid tooth" by 1828. Related: Cuspidate (adj.), which is attested from 1690s; cuspidal.

"spittoon," 1779, a colonial word, from Portuguese cuspidor "spittoon," from cuspir "to spit," from Latin conspuere "spit on," from assimilated form of com-, here probably an intensive prefix (see com-), + spuere "to spit" (see spew (v.)).

1775, American English dialectal, "troublesome person or animal" (usually with a defining adjective), a vulgar pronunciation of curse (n.), or else a shortening of the slang sense of customer. The word in the literal sense of "a curse" is from 1848.