action replay vs instant replay

action replay and instant replay both are nouns.

Word	Noun	Adjective	Verb	Adverb
action replay	Yes	No	No	No
instant replay	Yes	No	No	No

As nouns, action replay and instant replay are synonyms defined as:

action replay and instant replay: the immediate rebroadcast of some action (especially sports action) that has been recorded on videotape

Other synonyms of action replay include replay.

action replay (noun)	instant replay (noun)
the immediate rebroadcast of some action (especially sports action) that has been recorded on videotape	the immediate rebroadcast of some action (especially sports action) that has been recorded on videotape