揺ゆす

godan verb (-su), transitive verb

rock the left hand (for vibrato on a koto, etc.)

Archaic technical term for a koto playing technique; the modern verb is ゆする. Used in historical or traditional music contexts.

• 古ふるい箏ことの教きょう本ほんには「左ひだり手てを揺ゆす」という記き述じゅつが見みられる。

  In old koto instruction books, one can find descriptions like 'rock the left hand'.