Lewis & Short

exăgĭum, ii, n. [ex-ago; cf. examen, II.], a weighing, weight; a balance (late Lat.), Theod. et Val. Nov. 25; Inscr. Orell. 3166; cf. Ἐξάγιοϝ pensatio; ἐξαγιάζω examino, Gloss. Philox.