shelter vs sentry box

shelter and sentry box both are nouns.

Word	Noun	Adjective	Verb	Adverb
shelter	Yes	No	Yes	No
sentry box	Yes	No	No	No

As nouns, sentry box is a hyponym of shelter; that is, sentry box is a word with a more specific, narrower meaning than shelter:

shelter: protective covering that provides protection from the weather
sentry box: a small shelter with an open front to protect a sentry from the weather

Other hyponyms of shelter include bell cot, bell cote, birdhouse, canopy, cote, dog house, doghouse, kennel, lean-to, roost, sconce.

shelter (noun)	sentry box (noun)
a structure that provides privacy and protection from danger	a small shelter with an open front to protect a sentry from the weather
protective covering that provides protection from the weather
temporary housing for homeless or displaced persons
a way of organizing business to reduce the taxes it must pay on current earnings
the condition of being protected

shelter (verb)	sentry box (verb)
invest (money) so that it is not taxable
provide shelter for