bogmat vs duckweed

bogmat and duckweed both are nouns.

Word	Noun	Adjective	Verb	Adverb
bogmat	Yes	No	No	No
duckweed	Yes	No	No	No

As nouns, duckweed is a hypernym of bogmat; that is, duckweed is a word with a broader meaning than bogmat:

bogmat: having narrow flat sickle-shaped submerged fronds; North America
duckweed: any small or minute aquatic plant of the family Lemnaceae that float on or near the surface of shallow ponds

bogmat (noun)	duckweed (noun)
having narrow flat sickle-shaped submerged fronds; North America	any small or minute aquatic plant of the family Lemnaceae that float on or near the surface of shallow ponds