abandonment vs rejection

abandonment and rejection both are nouns.

Word	Noun	Adjective	Verb	Adverb
abandonment	Yes	No	No	No
rejection	Yes	No	No	No

As nouns, rejection is a hypernym of abandonment; that is, rejection is a word with a broader meaning than abandonment:

abandonment (noun)	rejection (noun)
withdrawing support or help despite allegiance or responsibility	the act of rejecting something
the voluntary surrender of property (or a right to property) without attempting to reclaim it or give it away	the speech act of rejecting
the act of giving something up	(medicine) an immunological response that refuses to accept substances or organisms that are recognized as foreign
	the state of being rejected