pea vs pigeon pea

pea and pigeon pea both are nouns.

Word	Noun	Adjective	Verb	Adverb
pea	Yes	No	No	No
pigeon pea	Yes	No	No	No

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

Other hyponyms of pea include garden pea, green pea, marrowfat pea, cajan pea, dahl, field pea.

pea (noun)	pigeon pea (noun)
seed of a pea plant used for food	small highly nutritious seed of the tropical pigeon-pea plant
a leguminous plant of the genus Pisum with small white flowers and long green pods containing edible green seeds	tropical woody herb with showy yellow flowers and flat pods; much cultivated in the tropics
the fruit or seed of a pea plant