Section Eight vs sacking

Section Eight and sacking both are nouns.

Word	Noun	Adjective	Verb	Adverb
Section Eight	Yes	No	No	No
sacking	Yes	No	No	No

As nouns, sacking is a hypernym of Section Eight; that is, sacking is a word with a broader meaning than Section Eight:

Section Eight: a discharge from the US Army based on unfitness or character traits deemed undesirable
sacking: the termination of someone's employment (leaving them free to depart)

Other hypernyms of Section Eight include discharge, dismissal, dismission, firing, liberation, release, sack.

Section Eight (noun)	sacking (noun)
a discharge from the US Army based on unfitness or character traits deemed undesirable	the termination of someone's employment (leaving them free to depart)
a soldier who received a Section Eight discharge as unfit for military service	coarse fabric used for bags or sacks