Nouns

(n)stifle, kneejoint between the femur and tibia in a quadruped; corresponds to the human knee

Verbs

(v)smother, stifle, strangle, muffle, represssuppress in order to conceal or hide“smother a yawn”, “muffle one's anger”, “strangle a laugh”, “repress a cry of fear”
(v)stifle, dampensuppress or constrain so as to lessen in intensity“Stifle your curiosity”
(v)suffocate, stifle, asphyxiate, chokeimpair the respiration of or obstruct the air passage of“The foul air was slowly suffocating the children”
(v)suffocate, stifle, asphyxiatebe asphyxiated; die from lack of oxygen“The child suffocated under the pillow”