offence vs push back

offence and push back both are nouns.

Word	Noun	Adjective	Verb	Adverb
offence	Yes	No	No	No
push back	Yes	No	Yes	No

As nouns, push back is a hyponym of offence; that is, push back is a word with a more specific, narrower meaning than offence:

Other hyponyms of offence include counteroffensive, dirty war, rollback.

offence (noun)	push back (noun)
the action of attacking an enemy	the act of forcing the enemy to withdraw
a transgression that constitutes a violation of what is judged to be right
a lack of politeness; a failure to show regard for others; wounding the feelings of others
a feeling of anger caused by being offended
the team that has the ball (or puck) and is trying to score

offence (verb)	push back (verb)
	cause to move back by force or influence