lockdown vs imprisonment

lockdown and imprisonment both are nouns.

Word	Noun	Adjective	Verb	Adverb
lockdown	Yes	No	No	No
imprisonment	Yes	No	No	No

As nouns, imprisonment is a hypernym of lockdown; that is, imprisonment is a word with a broader meaning than lockdown:

lockdown: the act of confining prisoners to their cells (usually to regain control during a riot)
imprisonment: the act of confining someone in a prison (or as if in a prison)

Other hypernyms of lockdown include internment.

lockdown (noun)	imprisonment (noun)
the act of confining prisoners to their cells (usually to regain control during a riot)	the act of confining someone in a prison (or as if in a prison)
	putting someone in prison or in jail as lawful punishment
	the state of being imprisoned