ăcernus: a, um, adj. 1. ăcer,I made of maple: equus trabibus contextus acernis, Verg. A. 2, 112; 9, 87: solio, ib. 8, 178: mensa, Hor. S. 2, 8, 10; cf. Mart. 14, 90: mensae, Ov. Met. 12, 254 al.