Lewis & Short

ĭn-ĭmĭtābĭlis, e, adj., that cannot be imilated, inimitable (post-Aug.): auctoritas, Quint. 8, 3, 25: mellis inimitabilis humanae rationi sapor, id. 1, 10, 7: dulcedo morum, Vell. 2, 97.