soybean vs bean

soybean and bean both are nouns.

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

As nouns, bean is a hypernym of soybean; that is, bean is a word with a broader meaning than soybean:

soybean: the most highly proteinaceous vegetable known; the fruit of the soybean plant is used in a variety of foods and as fodder (especially as a replacement for animal protein)
bean: any of various edible seeds of plants of the family Leguminosae used for food

Other hypernyms of soybean include edible bean.

As nouns, bean is a hypernym of soybean; that is, bean is a word with a broader meaning than soybean:

soybean (noun)	bean (noun)
the most highly proteinaceous vegetable known; the fruit of the soybean plant is used in a variety of foods and as fodder (especially as a replacement for animal protein)	informal terms for a human head
erect bushy hairy annual herb having trifoliate leaves and purple to pink flowers; extensively cultivated for food and forage and soil improvement but especially for its nutritious oil-rich seeds; native to Asia	any of various edible seeds of plants of the family Leguminosae used for food
a source of oil; used for forage and soil improvement and as food	any of various leguminous plants grown for their edible seeds and pods
	any of various seeds or fruits that are beans or resemble beans

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