quag vs quagmire

quag and quagmire both are nouns.

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

As nouns, quag and quagmire are synonyms defined as:

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

Other synonyms of quag include mire, morass, slack.

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