prefix
honorific or polite prefix
Archaic honorific prefix, historically attached to nouns to show respect. In modern Japanese, it is largely replaced by お or ご, and survives only in a few fossilized words like おみおつけ (miso soup).
「おみおつけ」の「おみ」は古い敬語の接頭辞です。
The おみ in おみおつけ is an old honorific prefix.
The prefix おみ is an ancient honorific form, likely derived from 大御 (おおみ), a combination of 大 (great) and 御 (honorable). It fell out of productive use and survives only in a few lexicalized compounds.