Lewis & Short

ăcĭnus, i, m., and ăcĭnum, i, n., partic. in plur. acina, orum (also ăcĭna, ae, f., Cat. 27, 4).

  1. I. A berry, esp. the grape, Col. 11, 2, 60; also: hederae sambucique, Plin. 15, 24, 29, § 100 sq.: cissanthemi, ib. 25, § 116: ligustri, ib. 24, 74: trychni, ib. 21, § 177.
  2. II. Per meton., the stone of a berry, Cic. Sen. 15, 52.