inimitabilis
From LSJ
ξυνῆλθεν ἀτταγᾶς τε καὶ νουμήνιος → birds of a feather flock together, the francolin and the new-moon bird get together
Latin > English (Lewis & Short)
ĭn-ĭmĭtābĭlis: e, adj.,
I 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.