air-guitar

listen to the pronunciation of air-guitar
English - English
To play the air guitar
An imaginary guitar that a listener to (usually rock) music pretends to play

I was embarrassed when a girl I knew walked in on my friends and I playing air guitar.

{i} (Informal) imaginary guitar that a person holds pretending to play a real guitar especially when miming to rock music; act of pretending to play a real guitar