This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
諃 combines 言 (speech) with 林 (grove), but the exact historical development is uncertain. It may have originally related to speaking in a certain manner, but no clear etymology is established.
With 言 (speech) beside 林 (grove), imagine someone speaking well among the trees, as the kun reading よくいう suggests 'to speak well'. However, the meaning is uncertain, so treat this as a tentative mnemonic.
For チン, picture a chin resting on a hand while listening to someone speak well in a grove: chin -> チン.