grime vs begrime

grime is a noun but begrime is not a noun.

Word	Noun	Adjective	Verb	Adverb
grime	Yes	No	Yes	No
begrime	No	No	Yes	No

As verbs, grime and begrime are synonyms defined as:

Other synonyms of grime include bemire, colly, dirty, soil.

grime (noun)	begrime (noun)
anything regarded as making something unclean

grime (verb)	begrime (verb)
make soiled, filthy, or dirty	make soiled, filthy, or dirty