bean vs mung bean

bean and mung bean both are nouns.

Word	Noun	Adjective	Verb	Adverb
bean	Yes	No	Yes	No
mung bean	Yes	No	No	No

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

bean: any of various edible seeds of plants of the family Leguminosae used for food
mung bean: seed of the mung bean plant used for food
mung bean: food from the seed of the mung bean plant

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

bean (noun)	mung bean (noun)
informal terms for a human head	seed of the mung bean plant used for food; food from the seed of the mung bean plant
any of various edible seeds of plants of the family Leguminosae used for food	erect bushy annual widely cultivated in warm regions of India and Indonesia and United States for forage and especially its edible seeds; chief source of bean sprouts used in Chinese cookery; sometimes placed in genus Phaseolus
any of various leguminous plants grown for their edible seeds and pods	seed of the mung bean plant; used for food; seed of the mung bean plant
any of various seeds or fruits that are beans or resemble beans

bean (verb)	mung bean (verb)
hit on the head, especially with a pitched baseball