silt up vs clog

silt up is not a noun while clog is a noun.

Word	Noun	Adjective	Verb	Adverb
silt up	No	No	Yes	No
clog	Yes	No	Yes	No

As verbs, clog is a hypernym of silt up; that is, clog is a word with a broader meaning than silt up:

Other hypernyms of silt up include back up, choke, choke off, clog up, congest, crap up, foul.

silt up (noun)	clog (noun)
	a dance performed while wearing shoes with wooden soles; has heavy stamping steps
	any object that acts as a hindrance or obstruction
	footwear usually with wooden soles

silt up (verb)	clog (verb)
become chocked with silt	impede with a clog or as if with a clog
	fill to excess so that function is impaired
	coalesce or unite in a mass
	become or cause to become obstructed
	impede the motion of, as with a chain or a burden
	dance a clog dance