Unqualified kid occasionally wails (5)
I believe the answer is:
total
'unqualified' is the definition.
(synonyms)
'kid occasionally wails' is the wordplay.
'kid' becomes 'tot' (tot is a kind of kid).
'occasionally' indicates alternate letters (letters taken at regular intervals or occasions).
The alternate letters of 'wails' are 'al'.
'tot'+'al'='TOTAL'
(Other definitions for total that I've seen before include "Sum, aggregation" , "Complete sum" , "It might be grand" , "Including all" , "Completely destroy" .)