shelter vs lean-to

shelter and lean-to both are nouns.

Word	Noun	Adjective	Verb	Adverb
shelter	Yes	No	Yes	No
lean-to	Yes	No	No	No

As nouns, lean-to is a hyponym of shelter; that is, lean-to is a word with a more specific, narrower meaning than shelter:

Other hyponyms of shelter include bell cot, bell cote, birdhouse, canopy, cote, dog house, doghouse, kennel, roost, sconce, sentry box.

shelter (noun)	lean-to (noun)
a structure that provides privacy and protection from danger	rough shelter whose roof has only one slope
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)	lean-to (verb)
invest (money) so that it is not taxable
provide shelter for