limit vs lessen

limit is a noun but lessen is not a noun.

Word	Noun	Adjective	Verb	Adverb
limit	Yes	No	Yes	No
lessen	No	No	Yes	No

As verbs, lessen is a hypernym of limit; that is, lessen is a word with a broader meaning than limit:

Other hypernyms of limit include decrease, minify.

limit (noun)	lessen (noun)
the greatest possible degree of something
the boundary of a specific area
as far as something can go
the greatest amount of something that is possible or allowed
the mathematical value toward which a function goes as the independent variable approaches infinity
final or latest limiting point

limit (verb)	lessen (verb)
restrict or confine within limits	decrease in size, extent, or range
place limits on (extent or amount or access)	wear off or die down
decide upon or fix definitely	make become smaller