ling ko vs water chestnut

ling ko and water chestnut both are nouns.

Word	Noun	Adjective	Verb	Adverb
ling ko	Yes	No	No	No
water chestnut	Yes	No	No	No

As nouns, water chestnut is a hypernym of ling ko; that is, water chestnut is a word with a broader meaning than ling ko:

ling ko: water chestnut whose spiny fruit has two rather than 4 prongs
water chestnut: a plant of the genus Trapa bearing spiny four-pronged edible nutlike fruits

Other hypernyms of ling ko include caltrop, water chestnut plant.

ling ko (noun)	water chestnut (noun)
water chestnut whose spiny fruit has two rather than 4 prongs	edible bulbous tuber of a Chinese marsh plant
	Chinese sedge yielding edible bulb-shaped tubers
	a plant of the genus Trapa bearing spiny four-pronged edible nutlike fruits