A tropical tree (also called 'rach' or known by its scientific name Teramnus labialis) or another variant referring to certain legume plants.
From Arabic or Persian origins, the word entered English through trade routes in the 16th-17th centuries. The exact etymology is disputed but likely relates to similar words for climbing or twining plants.
Arach is a relatively obscure English word that shows how plant names can vary dramatically across cultures and languages—the same plant might be called completely different things depending on which country you visit!
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