Oddly chatty man (3)
I believe the answer is:
'man' is the definition.
'oddly chatty' is the wordplay.
'oddly' indicates alternate letters.
The alternate letters of 'chatty' are 'CAT'.
(Other definitions for cat that I've seen before include "Animal - one with nine tails!" , "eg Leopard" , "Lash < jazz fan" , "See 21" , "Feline mammel" .)