em·bou·chure | \ ˈäm-bü-ˌshu̇r , ˌäm-bü-ˈshu̇r\
1: the position and use of the lips, tongue, and teeth in playing a wind instrument
2: the mouthpiece of a musical instrument
First Known Use
1760, in the meaning defined at sense 1
French, from (s')emboucher to flow into, from en- + bouche mouth
"Please remember that in this class, your mouth is to be used for forming an embouchure, and not for talking!"
(Middle school band instructor)