removal vs dismissal

removal and dismissal both are nouns.

Word	Noun	Adjective	Verb	Adverb
removal	Yes	No	No	No
dismissal	Yes	No	No	No

As nouns, dismissal is a hypernym of removal; that is, dismissal is a word with a broader meaning than removal:

removal: dismissal from office
dismissal: the termination of someone's employment (leaving them free to depart)

Other hypernyms of removal include discharge, dismission, firing, liberation, release, sack, sacking.

removal (noun)	dismissal (noun)
the act of removing	the termination of someone's employment (leaving them free to depart)
dismissal from office	a judgment disposing of the matter without a trial
	official notice that you have been fired from your job
	permission to go; the sending away of someone