Ass (#), n. [OE. asse, AS. assa; akin to Icel. asni, W. asen, asyn, L. asinus, dim. aselus, Gr. ; also to AS. esol, OHG. esil, G. esel, Goth. asilus, Dan. aesel, Lith. asilas, Bohem. osel, Pol. osiel. The word is prob. of Semitic origin; cf. Heb. athn she ass. Cf. Ease.]
1. Zool.
A quadruped of the genus Equus (E. 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.
Shak.
Asses' Bridge. [L. pons asinorum.] 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.
© Webster 1913.