bean
Synonym discussion
Sense: noun/1
'Bean' is the everyday word for many edible seeds and pods, especially larger ones such as black beans, kidney beans, or green beans. 'Pea' usually means the small round green seed, while 'lentil' names the flat disk-shaped seed often used in soup or curry. 'Pulse' is a broader food word for dried beans, peas, and lentils, common in nutrition writing but less common in daily speech. 'Legume' is the scientific umbrella term for the whole plant family, including the plants as well as the seeds. So a cook buys black beans, a child eats peas, a recipe asks for red lentils, and a health article may praise pulses or legumes.
Etymology
Bean is a very old Germanic word. Old English had bēan for this kind of edible seed, and related forms still appear in words such as Dutch boon and German Bohne. The basic meaning has changed little over time. Later English also used the word for other seeds with a similar shape, such as coffee beans, and then informally for a person's head because of the rough shape comparison.