This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
悢 combines 忄 (heart/mind) with 良, which likely contributes the sound. The exact historical development is uncertain.
With 忄 (heart) beside 良 (good), imagine a heart that longs for goodness but is left sad. This fits the kun-reading かな.しむ (to grieve).
For リョウ, picture a sad heart (忄) looking at a good (良) friend named Ryo who is leaving: Ryo -> リョウ, and the heart grieves.