What is the meaning of stifle?

noun

• Joint between the femur and tibia in a quadruped; corresponds to the human knee.
  • synonyms: knee

verb

• Conceal or hide.
  • usage: "smother a yawn"; "muffle one's anger"; "strangle a yawn"
  • synonyms: smother, strangle, muffle, repress
• Smother or suppress.
  • usage: "Stifle your curiosity"
  • synonyms: dampen
• Impair the respiration of or obstruct the air passage of.
  • usage: "The foul air was slowly suffocating the children"
  • synonyms: suffocate, asphyxiate, choke
• Be asphyxiated; die from lack of oxygen.
  • usage: "The child suffocated under the pillow"
  • synonyms: suffocate, asphyxiate