concentrate vs lessen

concentrate is a noun but lessen is not a noun.

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

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

Other hypernyms of concentrate include decrease, minify.

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

Other hypernyms of concentrate include decrease, diminish, fall.

concentrate (noun)	lessen (noun)
a concentrated example of something
a concentrated form of a foodstuff; the bulk is reduced by removing water
the desired mineral that is left after impurities have been removed from mined ore

concentrate (verb)	lessen (verb)
cook until very little liquid is left	decrease in size, extent, or range
make denser, stronger, or purer	wear off or die down
make central	make become smaller
be cooked until very little liquid is left
make more concise
compress or concentrate
direct one's attention on something
draw together or meet in one common center