Online Etymology Dictionary

subpoena (n.): early 15c., sub pena, from Medieval Latin sub poena "under penalty," the first words of the writ commanding the presence of someone under penalty of failure, from Latin sub "under" (see sub-) + poena, ablative of poena "penalty" (see penal). The verb is attested from 1630s.
subprime (adj.): also sub-prime, of loans, etc., by 1978, in frequent use from 1996, from sub- + prime (adj.).
subregion (n.): also sub-region, 1830, from sub- + region (n.). Related: Subregional.
subreption (n.): "act of obtaining a favor by fraudulent suppression of facts," c. 1600, from Latin subreptionem (nominative subreptio), noun of action from past participle stem of subripere, surripere (see surreptitious). Related: Subreptitious.
subrogate (v.): "to substitute," 1530s, from Latin subrogatus, variant of surrogatus, past participle of subrogare/surrogare "put in another's place, substitute, cause to be chosen in place of another" (see surrogate). Related: Subrogated; subrogating.
subrogation (n.): early 15c., "irregular or unlawful placement of someone in an office," from Middle French subrogation and directly from Latin subrogationem (nominative subrogatio), noun of action from past participle stem of subrogare (see subrogate).
subscribe (v.): early 15c., "to sign at the bottom of a document," from Latin subscribere "write, write underneath, sign one's name; register," also figuratively "assent, agree to, approve," from sub "underneath" (see sub-) + scribere "write" (see script (n.)). The meaning "give one's consent" (by subscribing one's name) first recorded mid-15c.; that of "contribute money to" 1630s; and that of "become a regular buyer of a publication" 1711, all originally literal. Related: Subscribed; subscribing.
subscriber (n.): 1590s, agent noun from subscribe.
subscript (n.): 1704, "that which is written underneath," from Latin subscriptus, past participle of subscribere "write underneath" (see subscribe).
subscription (n.): c. 1400, "piece of writing at the end of a document," from Middle French subscription (Modern French souscription) and directly from Latin subscriptionem (nominative subscriptio) "anything written underneath, a signature," noun of action from past participle stem of subscribere (see subscribe). Meaning "act of subscribing money" is from 1640s.
subsection (n.): also sub-section, 1620s, from sub- + section (n.).
subsequence (n.): c. 1500, from Late Latin subsequentia "act of following, succession," from Latin subsequens (see subsequent). Related: Subsequency.
subsequent (adj.): "following in time, later," mid-15c., from Middle French subsequent (14c.) and directly from Latin subsequentem (nominative subsequens), present participle of subsequi "come after in time, follow closely," figuratively "imitate, conform to," from sub "closely, up to" (see sub-) + sequi "follow" (see suit (n.)). Related: Subsequently; subsequential.
subservience (n.): 1670s, from subservient + -ence. Related: Subserviency (1620s).
subservient (adj.): 1630s, "useful, serviceable," from Latin subservientem (nominative subserviens), present participle of subservire "assist, serve, come to the help of, lend support," from sub "under" (see sub-) + servire "serve" (see serve (v.)). The meaning "slavishly obedient" is first recorded 1794. Related: Subserviently.
subset (n.): also sub-set, "subordinate set," 1897, originally in mathematics, from sub- + set (n.1).
subside (v.): 1680s, of objects, "to sink to the bottom," from Latin subsidere "sit down, settle, sink, fall; remain; crouch down, squat," from sub "down" (see sub-) + sidere "to settle," related to sedere "to sit" (see sedentary). Of liquid surfaces, "to sink to a lower level, be reduced" from 1706. Related: Subsided; subsiding.
subsidence (n.): 1650s, "a settling to the bottom," from Latin subsidentia "a settling down," from subsidens, from subsidere (see subside (v.)).
subsidiarity (n.): 1936, from German Subsidiarität, paraphrasing the Latin of Pius XI in his Quadragesimo Anno of 1931; see subsidiary + -ity.
subsidiary (adj.): 1540s, from Latin subsidiarius "belonging to a reserve, of a reserve, reserved; serving to assist or supplement," from subsidium "a help, aid, relief, troops in reserve" (see subsidy). As a noun, c. 1600, "subsidiary thing." In Latin the word was used as a noun meaning "the reserve."
subsidise (v.): chiefly British English spelling of subsidize. For suffix, see -ize. Related: Subsidised; subsidising.
subsidize (v.): 1755, from subsidy + -ize. Originally "to pay to hire" (mercenaries, foreign troops, etc.), also of nations, "to buy neutrality or alliance." Meaning "to bribe" is from 1815. Meaning "to support by grants of (often government) money" is from 1828. Related: Subsidized; subsidizing.
subsidy (n.): late 14c., from Anglo-French subsidie, Old French subside "help, aid, assistance, contribution," from Latin subsidium "a help, aid, assistance, (military) reinforcements, troops in reserve," from subsidere "to settle down, stay, remain" (see subside).
subsist (v.): 1540s, "to exist;" c. 1600, "retain the existing state," from Middle French subsister and directly from Latin subsistere "to stand still or firm, take a stand, take position; abide, hold out," from sub "under, up to" (see sub-) + sistere "to assume a standing position, stand still, remain; set, place, cause to stand still" (see assist (v.)). Meaning "to support oneself" (in a certain way) is from 1640s. Related: Subsisted; subsisting.
subsistence (n.): early 15c., "existence, independence," from Late Latin subsistentia "substance, reality," in Medieval Latin also "stability," from Latin subsistens, present participle of subsistere "stand still or firm" (see subsist). Latin subsistentia is a loan-translation of Greek hypostasis "foundation, substance, real nature, subject matter; that which settles at the bottom, sediment," literally "anything set under." In the English word, meaning "act or process of support for physical life" is from 1640s.
subsistent (adj.): 1520s, from Latin subsistentem (nominative subsistens), present participle of subsistere "stand still or firm" (see subsistence).
subsoil (n.): 1799, from sub- + soil (n.).
subsonic (adj.): also sub-sonic, 1937, from sub- + sonic. Compare supersonic.
subspecies (n.): 1690s, from sub- + species.
substance (n.): c. 1300, "essential nature, real or essential part," from Old French sustance, substance "goods, possessions; nature, composition" (12c.), from Latin substantia "being, essence, material," from substans, present participle of substare "stand firm, stand or be under, be present," from sub "up to, under" (see sub-) + stare "to stand," from PIE root *stā- "to stand" (see stet).

Latin substantia translates Greek ousia "that which is one's own, one's substance or property; the being, essence, or nature of anything." Meaning "any kind of corporeal matter" is first attested mid-14c. Sense of "the matter of a study, discourse, etc." first recorded late 14c.
substandard (adj.): also sub-standard, 1909, from sub- + standard (adj.).
substantial (adj.): mid-14c., "ample, sizeable," from Old French substantiel (13c.) and directly from Latin substantialis "having substance or reality, material," in Late Latin "pertaining to the substance or essence," from substantia "being, essence, material" (see substance). Meaning "existing, having real existence" is from late 14c. Meaning "involving an essential part or point" is early 15c. Related: Substantially.
substantiate (v.): 1650s, "to make real, to give substance to," from Modern Latin substantiatus, past participle of substantiare, from Latin substantia "being, essence, material" (see substance). Meaning "to demonstrate or prove" is attested from 1803. Related: Substantiated; substantiating.
substantiation (n.): 1760, "embodiment;" 1832, "the making good of a statement, the act of proving," noun of action from substantiate.
substantive (adj.): mid-15c., "standing by itself," from Old French substantif, from Late Latin substantivus "of substance or being, self-existent," from Latin substantia "being, essence, material" (see substance). The grammatical term (late 14c.) was introduced by the French to denote the noun in contradistinction to the adjective, from Latin nomen substantivum "name or word of substance." Related: Substantival; substantively.
substantive (n.): in grammatical use, late 14c., short for noun substantive, from Late Latin substantivium, neuter of substantivus "of substance or being" (see substantive (adj.)). Latin nomen substantivum was "name or word of substance."
substation (n.): also sub-station, 1864 in the policing sense, from sub- + station (n.). Power grid sense is attested from 1889.
substitute (v.): early 15c. (transitive), from Latin substitutus, past participle of substituere "put in place of another" (see substitution). Transitive use is from 1888. Related: Substituted; substituting.
substitute (n.): "one who acts in place of another," early 15c., from Middle French substitut (noun use) and directly from Latin substitutus, past participle of substituere "put in place of another" (see substitution). Military draft sense is from 1777, American English. Team sports sense is from 1849. Of foodstuffs, from 1879. As an adjective from early 15c.
substitution (n.): late 14c., "appointment of a subordinate or successor," from Middle French substitution or directly from Late Latin substitutionem (nominative substitutio) "a putting in place of (another)," noun of action from past participle stem of Latin substituere "put in place of another, place under or next to, present, submit," from sub "under" (see sub-) + statuere "set up," from PIE root *stā- "to stand," with derivatives meaning "place or thing that is standing" (see stet).
substract (v.): "to subtract," 1540s, "now illiterate" [OED], "An erroneous form of subtract, common in vulger use" [Century Dictionary], from Modern Latin substractus, past participle of substrahere, alternative form of subtrahere (see subtraction). Related: Subtracted; subtracting.
substrate (n.): 1810, from Modern Latin substratum (see substratum).
substratum (n.): 1630s, from Modern Latin substratum (plural substrata), noun use of neuter singular past participle of Latin substernere "to spread underneath," from sub- (see sub-) + sternere (see stratum).
substructure (n.): 1726, "foundation, part of a building which supports another part," from sub- + structure (n.). Earlier in this sense was substruction (1620s). Related: Substructural.
subsume (v.): 1530s, from Modern Latin subsumere "to take under," from Latin sub "under" (see sub-) + sumere "to take" (see exempt (adj.)). Related: Subsumed; subsuming, subsumption.
subtend (v.): 1560s, from Latin subtendere "to stretch underneath," from sub "under" (see sub-) + tendere "to stretch" (see tenet). Related: Subtended; subtending.
subterfuge (n.): 1570s, from Middle French subterfuge (14c.) or directly from Medieval Latin subterfugium "an evasion," from Latin subterfugere "to evade, escape, flee by stealth," from subter "beneath, below;" in compounds "secretly" (from PIE *sup-ter-, suffixed (comparative) form of *(s)up-; see sub-) + fugere "flee" (see fugitive (adj.)).
subterranean (adj.): c. 1600, from Latin subterraneus "underground," from sub "under" (see sub-) + terra "earth, the ground" (see terrain) + -an.
subtext (n.): "underlying theme of a work of literature," 1950, from sub- + text (n.). Originally a term in Konstantin Stanislavsky's theory of acting. Earlier it was used in a literally sense of "text appearing below other text on a page" (1726). Latin subtextere meant "to weave under, work in below."
subtile (adj.): late 14c., "clever, dexterous, crafty; not dense, thin, rarefied," from Old French subtil (14c.), a learned Latinized reformation of earlier sotil (12c.), source of subtle (q.v.). Still used in some Bible translations in Gen. iii:1, and it survived after 17c. as a parallel formation to subtle in some material senses ("fine, delicate, thin").