concentrate vs absorb

concentrate is a noun but absorb is not a noun.

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

As verbs, absorb is a hyponym of concentrate; that is, absorb is a word with a more specific, narrower meaning than concentrate:

Other hyponyms of concentrate include engross, engulf, immerse, plunge, soak up, steep, recall, think, zoom in, hear, listen, take heed.

concentrate (noun)	absorb (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)	absorb (verb)
cook until very little liquid is left	cause to become one with
make denser, stronger, or purer	take up mentally
make central	consume all of one's attention or time
be cooked until very little liquid is left	devote (oneself) fully to
make more concise	take in, also metaphorically
compress or concentrate	become imbued
direct one's attention on something	assimilate or take in
draw together or meet in one common center	take up, as of debts or payments
	suck or take up or in