Stale rhyme to make you cry! (4)
I believe the answer is:
wail
'cry' is the definition.
(wailing is a kind of crying)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for wail that I've seen before include "Long cry, as of siren" , "(Make a) plaintive cry" , "Lament audibly" , "Cry of grief" , "Cry, moan" .)