rot vs decompose

rot is a noun but decompose is not a noun.

Word	Noun	Adjective	Verb	Adverb
rot	Yes	No	Yes	No
decompose	No	No	Yes	No

As verbs, rot and decompose are synonyms defined as:

Other synonyms of rot include molder, moulder.

rot (noun)	decompose (noun)
unacceptable behavior (especially ludicrously false statements)
(biology) the process of decay caused by bacterial or fungal action
a state of decay usually accompanied by an offensive odor

rot (verb)	decompose (verb)
become physically weaker	separate (substances) into constituent elements or parts
break down	break down
	lose a stored charge, magnetic flux, or current