Daughter is wanting long hair, the pain! (8)
I believe the answer is:
distress
'the pain' is the definition.
(distress is a kind of pain)
'daughter is wanting long hair' is the wordplay.
'daughter' becomes 'dis' (I've seen this in other clues).
'is wanting' means one lot of letters go next to another.
'long hair' becomes 'tress' (I've seen this before).
'dis'+'tress'='DISTRESS'
(Other definitions for distress that I've seen before include "Severe pain" , "Mayday is such a signal." , "Extreme sorrow or pain" , "Affliction" , "Upset" .)