caltrop vs ling ko

caltrop and ling ko both are nouns.

Word	Noun	Adjective	Verb	Adverb
caltrop	Yes	No	No	No
ling ko	Yes	No	No	No

As nouns, ling ko is a hyponym of caltrop; that is, ling ko is a word with a more specific, narrower meaning than caltrop:

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

Other hyponyms of caltrop include Jesuits' nut, Trapa natans, water caltrop, ling, Trapa bicornis.

caltrop (noun)	ling ko (noun)
tropical annual procumbent poisonous subshrub having fruit that splits into five spiny nutlets; serious pasture weed	water chestnut whose spiny fruit has two rather than 4 prongs
Mediterranean annual or biennial herb having pinkish to purple flowers surrounded by spine-tipped scales; naturalized in America
a plant of the genus Trapa bearing spiny four-pronged edible nutlike fruits