Definition of "Muscle" :

noun: possessing muscular strength

noun: authority or power or force (especially when used in a coercive way)

"The senators used their muscle to get the party leader to resign."

noun: animal tissue consisting predominantly of contractile cells

noun: one of the contractile organs of the body

noun: a bully employed as a thug or bodyguard

"The drug lord had his muscleman to protect him."

verb: make one's way by force

"He muscled his way into the office."