This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
諿 combines 言 (speech) with 咠, but the exact historical development and original meaning are uncertain.
With 言 (speech) beside 咠, imagine words that soothe or calm, but remember the meaning is unclear.
For シュウ, picture someone saying 'shh' to calm a crowd: 'shh' cues シュウ, and the speech radical 言 fits the scene.