Definition of castrati:
(n) :
A male who has been castrated, especially a male whose testicles have been removed before puberty in order to retain his boyish voice.
(n) :
(music) A male soprano or alto voice produced by castration of the treble singer before puberty, intended to conserve his voice; the singer.
(adj) :
(literally) Castrated; especially castrated prepubescently.
(adj) :
Having, using or containing the voice of a castrato (noun).
(adj) :
Originally composed for a castrato.