For a shrub:
* Llwyn: This is the most common translation for "bush" as a shrub, meaning "a thicket, a clump of trees, a bush".
* Brwyn: This word can also be used for a shrub, but it specifically refers to a "bramble, a briar, a thorny bush".
For other meanings of "bush":
* Celyn: This word means "holly" and can be used in contexts where "bush" refers to a specific type of shrub like holly.
* Coed bach: Literally means "small tree," this could be used when referring to a smaller type of tree that resembles a bush.
* Cymdeithas: For the slang term "bush" used to describe a "crowd" or "group" of people, "cymdeithas" can be used, although it has a broader meaning of "society" or "community".
It's best to consider the specific context you want to use "bush" in, and choose the most appropriate translation based on its meaning.