Slang definitions & phrases for flex one's muscles
flex one's muscles
verb phrase
To give a sample of one's power, esp in a threatening way: I'm not sure they mean harm, probably just flexing their muscles(1960s+)
Idioms and Phrases with flex one's muscles
flex one's muscles
Show off one's strength or power, as in The boys love flexing their muscles, or The new department head has decided to flex her muscles. [ Early 1900s ]