bog vs bog down

bog is a noun but bog down is not a noun.

Word	Noun	Adjective	Verb	Adverb
bog	Yes	No	Yes	No
bog down	No	No	Yes	No

As verbs, bog and bog down are synonyms defined as:

As verbs, bog and bog down are synonyms defined as:

bog (noun)	bog down (noun)
wet spongy ground of decomposing vegetation; has poorer drainage than a swamp; soil is unfit for cultivation but can be cut and dried and used for fuel

bog (verb)	bog down (verb)
cause to slow down or get stuck	cause to slow down or get stuck
get stuck while doing something	get stuck while doing something
	be unable to move further
	cause to get stuck as if in a mire