豆

It literally stands for "bean" and is used to refer to beans or legumes in general.

The character 豆 is a pictograph originally depicting a lidded vessel with a footed base (a kind of ritual vessel used in ancient ceremonies).

It was initially used to mean "ritual vessel" (祭器). However, through the process of phonetic loaning, its meaning shifted and it came to primarily represent "bean" (콩) in modern usage. This is one of the rare cases where the phonetic loan resulted in a concrete meaning rather than an abstract one.