late 14c., "emit from a confined space," probably a shortening of aventer "expose oneself to the air" (c. 1300), from Old French eventer "let out, expose to air," from Vulgar Latin *exventare, from Latin ex "out" + ventus "wind" (from PIE *wē-nt-o‑ "blowing," suffixed (participial) form of root *we- "to blow").
Sense of "express freely" first recorded 1590s. Sense of "divulge, publish" (1590s) is behind phrase vent one's spleen (see spleen). Related: Vented; venting.
wē-, Proto-Indo-European root meaning "to blow."
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit va-, Greek aemi-, Gothic waian, Old English wawan, Old High German wajan, German wehen, Old Church Slavonic vejati "to blow;" Sanskrit vatah, Avestan vata-, Hittite huwantis, Latin ventus, Old English wind, German Wind, Gothic winds, Old Church Slavonic vetru, Lithuanian vėjas "wind;" Lithuanian vėtra "tempest, storm;" Old Irish feth "air;" Welsh gwynt, Breton gwent "wind."
It forms all or part of: abet; bait (n.) "food used to attract prey;" bait (v.) "to torment, persecute;" bateau; beetle (n.1) "type of insect; bit (n.1) "small piece;" bite; bitter; bitter end; boat; boatswain; -fid; fissile; fission; fissure; giblets; pita; pizza; vent (n.).
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit bhinadmi "I cleave," Latin Latin findere "to split, cleave, separate, divide," Old High German bizzan "to bite," Old English bita "a piece bitten off, morsel," Old Norse beita "to hunt with dogs," beita "pasture, food."
formerly also enveigh, late 15c., "to introduce," from Latin invehere "to bring in, carry in, introduce," also "assault, assail," from in- "against" (see in- (1)) + vehere "to carry" (from PIE root *wegh- "to go, move, transport in a vehicle"). Meaning "to give vent to violent denunciation" is from 1520s, from a secondary sense in Latin (see invective). Related: Inveighed; inveighing.
mid-14c., "roofed passage, vent for smoke," later "shed for animals" (mid-15c.), of unknown origin. The proposal that it is a diminutive of Old English hof "dwellings, farm" is "etymologically and chronologically inadmissible" [OED]. Meaning "shed for human habitation; rude or miserable cabin" is from 1620s. It also sometimes meant "canopied niche for a statue or image" (mid-15c.).
"hood attached to a gown or robe, chiefly worn by monks and characteristic of their profession; a hooded garment," Middle English coule, from Old English cule, from earlier cugele, from Late Latin cuculla "monk's cowl," variant of Latin cucullus "hood, cowl," which is of uncertain origin. As "covering (originally cowl-shaped) for the top of a chimney or vent-pipe" by 1812. Hence cowling for "removable engine cover," 1917, originally in reference to aircraft.
also cess-pool, "cistern or well to receive sediment or filth," 1670s, the first element perhaps an alteration of cistern, or perhaps a shortened form of recess [Klein]; or the whole may be an alteration of suspiral (c. 1400), "drainpipe," from Old French sospiral "a vent, air hole," from sospirer "breathe," from Latin suspirare "breathe deep" [Barnhart]. Meaning extended to "tank at the end of the pipe," which would account for a possible folk-etymology change in final syllable.
Other possible etymologies: Italian cesso "privy" [OED], from Latin secessus "place of retirement" (in Late Latin "privy, drain"); dialectal suspool, from suss, soss "puddle;" or cess "a bog on the banks of a tidal river."