用ひる

First attested in texts around the Kamakura period, persisting until around the script reforms in the 1920s.

The attestable root verb is 用ゐる (mochiwiru), itself a compound (see that entry for details). During the mid-Heian period, medial /-f-/ sounds shifted to /-w-/, leading to confusion between mid-word ゐ (wi) and ひ (wi, read as fi in word-initial position). The もちひる (mochiwiru) hiragana spelling was then reinterpreted as a conjugation of base verb もちふ (mochi(w)u), which appears as a back-formation. Later during the Kamakura and Muromachi periods, sound changes reduced medial /-w-/ still further, such that /wi/ merged into /i/. The resulting shift in the verb ending from -wiru to -iru was reinterpreted again as a conjugation of base form もちゆ (mochiyu), which again appears as a back-formation.[1][2]

用ひる (hiragana もちいる, rōmaji mochiiru, historical hiragana もちひる)

1. (obsolete, historical) Rare archaic alternative spelling of 用いる (mochiiru), historical 用ゐる (mochiwiru): to use
   • 1940s, Hajime Kawakami, 枕上浮雲:

     室内の歩行に杖を用ひず、階上への上り下りにも、さまで脚のだるきを感ぜず。

     (please add an English translation of this usage example)

• 用 (もち)ふ (mochifu)
• 用 (もち)ゆ (mochiyu)