This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
詇 combines 言 (speech) with 央, which likely contributes the sound. The exact historical meaning is uncertain.
With 言 (speech) on the left and 央 (center) on the right, imagine words spoken from the center of a group, but the exact meaning remains unclear.
For ヨウ, imagine a yo-yo spinning at the center of a conversation: yo -> ヨウ, and the words 言 come from the center 央.