Falsetto is a very high male voice, thin and flute-like, above a man’s usual singing or speaking range. Pop singers often slip into it for high notes; cartoon villains sometimes speak in it for a joke. Though actually, it is a way of using the voice — a register — not “a woman’s voice stuck on a man.” Women have a similar high, thin register too, but English speakers almost always point the word at men. It is not the same as a soprano’s natural high voice, and it is not simply “any high voice.” Borrowed from Italian falsetto, from falso, “false,” as if it were not the “true” chest voice.

假音（台灣唱歌、KTV 多說假音；中國大陸也常用假聲）