congest vs crap up

congest and crap up both are verbs.

Word	Noun	Adjective	Verb	Adverb
congest	No	No	Yes	No
crap up	No	No	Yes	No

As verbs, congest and crap up are synonyms defined as:

Other synonyms of congest include back up, choke, choke off, clog, clog up, foul.

congest (verb)	crap up (verb)
become or cause to become obstructed	become or cause to become obstructed