An involuntary intake of breath through a wide open mouth; usually triggered by fatigue or boredom:
— The yawning in the audience told him it was time to stop.

synonyms: oscitance, oscitancy, yawn.

Roget 688: fatigue; weariness etc. 841; yawning, drowsiness etc. 683; lassitude, tiredness, fatigation^†, exhaustion; sweat; dyspnoea.    anhelation, shortness of breath; faintness; collapse, prostration, swoon, fainting, deliquium [Lat.], syncope, lipothymy^†; goneness^†.    ... show more

Roget 260: hole, foramen; puncture, perforation; fontanel^†; transforation^†; pinhole, keyhole, loophole, porthole, peephole, mousehole, pigeonhole; eye of a needle; eyelet; slot.    opening; aperture, apertness^†; hiation^†, yawning, oscitancy^†, dehiscence, patefaction^†, pandiculation^†; chasm etc. (interval) 198.    embrasure, window, casement; abatjour^†; light; sky light, fan light; lattice; bay window, bow window; oriel [Arch.]; dormer, lantern.    outlet, inlet; vent, vomitory; embouchure; orifice, mouth, sucker, muzzle, throat, gullet, weasand^†, wizen, nozzle; placket.    portal, porch, gate, ostiary^†, postern, wicket, trapdoor, hatch, door; arcade; cellarway^†, driveway, gateway, doorway, hatchway, gangway; lich gate^†.    way, path etc. 627; thoroughfare; channel; passage, passageway; tube, pipe; water pipe etc. 350; air pipe etc. 351; vessel, tubule, canal, gut, fistula; adjutage^†, ajutage^†; ostium^†; smokestack; chimney, flue, tap, funnel, gully, tunnel, main; mine, pit, adit^†, shaft; gallery.    alley, aisle, glade, vista.    bore, caliber; pore; blind orifice; fulgurite^†, thundertube^†.    porousness, porosity.    sieve, cullender^†, colander; cribble^†, riddle, screen; honeycomb.    apertion^†, perforation; piercing etc. v.; terebration^†, empalement^†, pertusion^†, puncture, acupuncture, penetration.    key etc. 631, opener, master key, password, combination, passe-partout.    ... show more

Gaping open as if threatening to engulf someone or something.

Roget 208: deep, deep seated; profound, sunk, buried; submerged etc. 310; subaqueous, submarine, subterranean, subterraneous, subterrene^†; underground.    bottomless, soundless, fathomless; unfathomed, unfathomable; abysmal; deep as a well; bathycolpian^†; benthal^†, benthopelagic^†; downreaching^†, yawning.    knee deep, ankle deep.    ... show more

With the mouth wide open indicating boredom or sleepiness.

Showing lack of attention or boredom:
— The yawning congregation.

synonyms: drowsy, oscitant.

Roget 260: open; perforated etc. v.; perforate; wide open, ajar, unclosed, unstopped; oscitant^†, gaping, yawning; patent.    tubular, cannular^†, fistulous; pervious, permeable; foraminous^†; vesicular, vasicular^†; porous, follicular, cribriform^†, honeycombed, infundibular^†, riddled; tubulous^†, tubulated^†; piped, tubate^†.    opening etc. v.; aperient^†.    ... show more