胡頽子

First attested in 898.^[1]

Probably realized in older times as kumi with an unvoiced initial.^[1][2]

This appears in some dialects as guimi, suggesting a possible shift from that as an older form, which could be a derivation from ぐい (“poke”, in reference to the many thorns of the plant) + 実 (mi, “fruit”).

• (Tokyo) ぐみ [gúꜜmì] (Atamadaka – [1])^[2]
• IPA^(key): [ɡɯ̟mʲi]

胡頽子(ぐみ) or 胡頽子(グミ) • (gumi) 

1. silverberry, oleaster: plants in the genus Elaeagnus, or the fruit thereof

As with many terms that name organisms, this term is often spelled in katakana, especially in biological contexts (where katakana is customary).

• Entry in Nihon Jiten (in Japanese)