dismissal vs sacking

dismissal and sacking both are nouns.

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

As nouns, dismissal and sacking are synonyms defined as:

dismissal and sacking: the termination of someone's employment (leaving them free to depart)

Other synonyms of dismissal include discharge, dismission, firing, liberation, release, sack.

dismissal (noun)	sacking (noun)
the termination of someone's employment (leaving them free to depart)	the termination of someone's employment (leaving them free to depart)
a judgment disposing of the matter without a trial	coarse fabric used for bags or sacks
official notice that you have been fired from your job
permission to go; the sending away of someone