internment vs lockdown

internment and lockdown both are nouns.

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

As nouns, lockdown is a hyponym of internment; that is, lockdown is a word with a more specific, narrower meaning than internment:

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

Other hyponyms of internment include false imprisonment, custody.

internment (noun)	lockdown (noun)
the act of confining someone in a prison (or as if in a prison)	the act of confining prisoners to their cells (usually to regain control during a riot)
placing private property in the custody of an officer of the law
confinement during wartime