Lewis Short
attĕnŭātĭo | adt- (noun F) : (), , attenuo
* A diminishing, lessening (only in the two foll. exs.): attenuatio suspitionis, Auct. ad Her. 2, 2: verborum attenuatio,simplicity,id. ib. 4, 11; cf. attenuatus.
Charlton T. Lewis, Charles Short, A Latin Dictionary