steed (n.)

c. 1200, palefrei (mid-12c. as a surname), "saddle horse for ordinary riding (opposed to a war horse), a fine, small horse for ladies," from Old French palefroi (11c., palefreid) and directly from Medieval Latin palafredus, altered by dissimilation from Late Latin paraveredus "post horse for outlying districts" (6c.), originally "extra horse," from Greek para "beside, secondary" (see para-) + Medieval Latin veredus "post horse; light, fast horse used by couriers," which is probably from Gaulish *voredos, from Celtic *wo-red- (source also of Welsh gorwydd "horse," Old Irish riadaim "I ride"), from PIE root *reidh- "to ride" (see ride (v.)). The Latin word passed to Old High German as pfarifrid, and in modern German it has become the usual word for "horse" (Pferd).

[horse used for breeding] Middle English stode "a herd of horses; place where horses are kept" for breeding or any purpose, from Old English stod, from Proto-Germanic *stodo (source also of Old Norse stoð, Middle Low German stod, Old High German stuot "herd of horses," German Stute "mare").

This is reconstructed to be from PIE root *sta- "to stand, make or be firm," with derivatives meaning "place or thing that is standing" (source also of Old Church Slavonic stado "herd," Lithuanian stodas "a drove of horses").

The shift of sense to "male horse kept for breeding" is attested by 1803, originally colloquial, perhaps via or encouraged by the use of stud-book "publication giving pedigrees of current racing horses" (by 1793). The further-extended meaning "man who is highly active and proficient sexually" is attested by 1895, also extended to dogs. The meaning "any young man" is from 1929.

Studdery "place for keeping a stud of horses" is from 1580s. Stud-poker (1864) is said to be from stud-horse poker, but that phrase seems to be not found earlier than 1876.

Reno is a moral town. Our last faro bank has been compelled to close out business. The boys now play stud horse poker and pedro for amusement. [Weekly State Journal, Reno, Nevada, March 11, 1876]

*stā-, Proto-Indo-European root meaning "to stand, set down, make or be firm," with derivatives meaning "place or thing that is standing."

It forms all or part of: Afghanistan; Anastasia; apostasy; apostate; armistice; arrest; assist; astatic; astatine; Baluchistan; bedstead; circumstance; consist; constable; constant; constitute; contrast; cost; desist; destination; destine; destitute; diastase; distance; distant; ecstasy; epistasis; epistemology; establish; estaminet; estate; etagere; existence; extant; Hindustan; histidine; histo-; histogram; histology; histone; hypostasis; insist; instant; instauration; institute; interstice; isostasy; isostatic; Kazakhstan; metastasis; obstacle; obstetric; obstinate; oust; Pakistan; peristyle; persist; post (n.1) "timber set upright;" press (v.2) "force into service;" presto; prostate; prostitute; resist; rest (v.2) "to be left, remain;" restitution; restive; restore; shtetl; solstice; stable (adj.) "secure against falling;" stable (n.) "building for domestic animals;" stage; stalag; stalwart; stamen; -stan; stance; stanchion; stand; standard; stanza; stapes; starboard; stare decisis; stasis; -stat; stat; state (n.1) "circumstances, conditions;" stater; static; station; statistics; stator; statue; stature; status; statute; staunch; (adj.) "strong, substantial;" stay (v.1) "come to a halt, remain in place;" stay (n.2) "strong rope which supports a ship's mast;" stead; steed; steer (n.) "male beef cattle;" steer (v.) "guide the course of a vehicle;" stem (n.) "trunk of a plant;" stern (n.) "hind part of a ship;" stet; stoa; stoic; stool; store; stound; stow; stud (n.1) "nailhead, knob;" stud (n.2) "horse kept for breeding;" stylite; subsist; substance; substitute; substitution; superstition; system; Taurus; understand.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit tisthati "stands;" Avestan histaiti "to stand;" Persian -stan "country," literally "where one stands;" Greek histēmi "put, place, cause to stand; weigh," stasis "a standing still," statos "placed," stylos "pillar;" Latin sistere "stand still, stop, make stand, place, produce in court," status "manner, position, condition, attitude," stare "to stand," statio "station, post;" Lithuanian stojuos "I place myself," statau "I place;" Old Church Slavonic staja "place myself," stanu "position;" Gothic standan, Old English standan "to stand," stede "place;" Old Norse steði "anvil;" Old Irish sessam "the act of standing."