quag vs bog

quag and bog both are nouns.

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

As nouns, bog is a hypernym of quag; that is, bog is a word with a broader meaning than quag:

quag: a soft wet area of low-lying land that sinks underfoot
bog: 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

Other hypernyms of quag include peat bog.

quag (noun)	bog (noun)
a soft wet area of low-lying land that sinks underfoot	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

quag (verb)	bog (verb)
	cause to slow down or get stuck
	get stuck while doing something