Lewis & Short

ĭmĭtāmentum, i, n. [imitor], imitation; abstr. and concr. (post-Aug.): simulacrum imitamenti Olympiaci Jovis, the statue, Amm. 22, 13, 1.
In plur.: tristitiae, acts in imitation of, Tac. A. 13, 4: veterum Romanorum, id. ib. 14, 57: opplevit omnia non simulacris neque imitamentis, sed luctu atque lamentis veris, Gell. 7, 5, 7.