The action of thrusting one's clenched fist into the air, typically as a gesture of elation or triumph. Also: the action of delivering blows with the fist which do not strike a target.
Origin
1950s. From air + punching.
Definition of air-punching in US English:
air-punching
nounˈɛːpʌn(t)ʃɪŋ
The action of thrusting one's clenched fist into the air, typically as a gesture of elation or triumph. Also: the action of delivering blows with the fist which do not strike a target.