early 15c., "an opening, hole, orifice," from Latin apertura "an opening," from apertus, past participle of aperire "to open, uncover," from PIE compound *ap-wer-yo- from *ap- "off, away" (see apo-) + root *wer- (4) "to cover." In optics, diameter of the exposed part of a telescope, microscope, etc., 1660s.
It forms all or part of: ab-; abaft; ablaut; aft; after; apanthropy; aperitif; aperture; apo-; apocalypse; apocryphal; Apollyon; apology; apoplexy; apostle; apostrophe; apothecary; apotheosis; awk; awkward; ebb; eftsoons; of; off; offal; overt.
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit apa "away from," Avestan apa "away from," Greek apo "from, away from; after; in descent from," Latin ab "away from, from," Gothic af, Old English of "away from."
Proto-Indo-European root meaning "to cover."
It forms all or part of: aperitif; apertive; aperture; barbican; cover; covert; curfew; discover; garage; garment; garnish; garret; garrison; guarantee; guaranty; kerchief; landwehr; operculum; overt; overture; pert; warn; warrant; warrantee; warranty; warren; wat; Wehrmacht; weir.
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit vatah "enclosure," vrnoti "covers, wraps, shuts;" Lithuanian užveriu, užverti "to shut, to close;" Old Persian *pari-varaka "protective;" Latin (op)erire "to cover," (ap)erire "open, uncover" (with ap- "off, away"); Old Church Slavonic vora "sealed, closed," vreti "shut;" Old Irish feronn "field," properly "enclosed land;" Old English wer "dam, fence, enclosure," German Wehr "defense, protection," Gothic warjan "to defend, protect."
"an opening, a mouth or aperture," early 15c., from Old French orifice "the opening of a wound" (14c.) and directly from Late Latin orificium "an opening," literally "mouth-making," from Latin os (genitive oris) "mouth" (see oral) + combining form of facere "to make, do" (from PIE root *dhe- "to set, put"). Related: Orificial.
early 13c., "an aperture or opening," from open (adj.). Sense of "an open or clear space" is by 1796. The open "open country" is from 1620s; as "open air" from 1875. Meaning "public knowledge" (especially in out in the open) is from 1942, but compare Middle English in open (late 14c.) "manifestly, publicly." The sense of "an open competition" is from 1926, originally in a golf context.
c. 1400, dilatacioun, "act of expanding, expansion," especially "abnormal enlargement of an aperture of the body," from Old French dilatation and directly from Late Latin dilatationem (nominative dilatatio) "a widening," noun of state from past-participle stem of Latin dilatare "make wider, enlarge," from dis- "apart" (see dis-) + lātus "broad, wide, widespread, extended" (see latitude). Also in Middle English "amplification in discourse" (late 14c.). In gynecology dilatation and curettage is by 1896.