disengagement vs fallback

disengagement and fallback both are nouns.

Word	Noun	Adjective	Verb	Adverb
disengagement	Yes	No	No	No
fallback	Yes	No	No	No

As nouns, disengagement and fallback are synonyms defined as:

disengagement and fallback: to break off a military action with an enemy

Other synonyms of disengagement include pullout.

disengagement (noun)	fallback (noun)
to break off a military action with an enemy	to break off a military action with an enemy
the act of releasing from an attachment or connection