acacia: [16] Acacia comes via Latin from Greek akakía, a word for the shittah. This is a tree mentioned several times in the Bible (the Ark of the Covenant was made from its wood). It is not clear precisely what it was, but it was probably a species of what we now know as the acacia. The ultimate derivation of Greek akakía is obscure too; some hold that it is based on Greek aké ‘point’ (a distant relation of English acid), from the thorniness of the tree, but others suggest that it may be a loanword from Egyptian.
1540s, from Latin acacia, from Greek akakia "thorny Egyptian tree," perhaps related to Greek ake "point, thorn," from PIE root *ak- "sharp" (see acrid). Or perhaps a Hellenization of some Egyptian word. From late 14c. in English as the name of a type of gum used as an astringent, etc.
