wetland vs swamp

wetland and swamp both are nouns.

Word	Noun	Adjective	Verb	Adverb
wetland	Yes	No	No	No
swamp	Yes	No	Yes	No

As nouns, swamp is a hyponym of wetland; that is, swamp is a word with a more specific, narrower meaning than wetland:

wetland: a low area where the land is saturated with water
swamp: low land that is seasonally flooded; has more woody plants than a marsh and better drainage than a bog

Other hyponyms of wetland include bog, peat bog, fen, fenland, marsh, marshland, swampland.

wetland (noun)	swamp (noun)
a low area where the land is saturated with water	low land that is seasonally flooded; has more woody plants than a marsh and better drainage than a bog
	a situation fraught with difficulties and imponderables

wetland (verb)	swamp (verb)
	fill quickly beyond capacity; as with a liquid
	drench or submerge or be drenched or submerged