shorten vs concentrate

shorten is not a noun while concentrate is a noun.

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

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

Other hyponyms of shorten include bowdlerise, bowdlerize, castrate, expurgate, shorten, condense, digest.

shorten (noun)	concentrate (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

shorten (verb)	concentrate (verb)
become short or shorter	cook until very little liquid is left
make shorter than originally intended; reduce or retrench in length or duration	make denser, stronger, or purer
reduce in scope while retaining essential elements	make central
edit by omitting or modifying parts considered indelicate	be cooked until very little liquid is left
make short or shorter	make more concise
	compress or concentrate
	direct one's attention on something
	draw together or meet in one common center