Webster's Revised Unabridged Dictionary · 1913

Ass

Ass ({not transcribed}) , noun

[Old English asse, Anglo-Saxon assa; akin to Icelandic asni, Welsh asen, asyn, Latin asinus, dim. aselus, Greek {not transcribed}; also to Anglo-Saxon esol, Old High German esil, German esel, Gothic asilus, Danish asel, Lithuanian asilas, Bohem. osel, Pol. osiel. The word is prob. of Semitic origin; compare Hebrew ath{not transcribed}n she ass. Compare Ease.]

1.
(Zoology) A quadruped of the genus Equus (Equus asinus), smaller than the horse, and having a peculiarly harsh bray and long ears. The tame or domestic ass is patient, slow, and sure-footed, and has become the type of obstinacy and stupidity. There are several species of wild asses which are swift-footed.
2.
A dull, heavy, stupid fellow; a dolt. — Shakespeare
Collocations (2)
Asses' Bridge , The fifth proposition of the first book of Euclid, “The angles at the base of an isosceles triangle are equal to one another.” [Sportive] A schoolboy, stammering out his Asses' Bridge. — F. Harrison
To make an ass of one's self , to do or say something very foolish or absurd.