1. a method of voice production used by male singers, especially tenors, to sing notes higher than their normal range: "he sang in a piercing falsetto"
▪ a singer using falsetto.
▪ a voice or sound that is unusually or unnaturally high:"Philip answered in a prim falsetto"
Word Originlate 18th century: from Italian, diminutive of falso ‘false’, from Latin falsus (see false).
Vocal register just above the modal voice register
Falsetto is the vocal register occupying the frequency range just above the modal voice register and overlapping with it by approximately one octave. Wikipedia