Roman goddess of fruit trees and their culture, from Latin pomum "apple; fruit," a word of uncertain origin. "Possibly from *po-emo- 'taken off, picked'; *po-omo- or *pe-omo- are also conceivable" [de Vaan]. Or perhaps borrowed from a lost Mediterranean language. Related: Pomonical.
word-forming element denoting "belonging to, of the nature of," from Latin -aceus, enlarged form of adjectival suffix -ax (genitive -acis); see -acea. Especially in biology, "pertaining to X order of plants or animals."
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Harper, D. (n.d.). Etymology of pomaceous. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/pomaceous