Bill stopping dance to find girl's hat (9)
I believe the answer is:
balaclava
'hat' is the definition.
(I have seen 'Warm hat' mean 'balaclava' so perhaps 'hat' could also mean 'balaclava')
'bill stopping dance to find girl's' is the wordplay.
'bill' becomes 'ac'.
'stopping' is an insertion indicator (stopping can mean blocking a gap).
'dance' becomes 'ball' (ball is a kind of dance).
'to find girl' becomes 'ava' (I can't explain this - if you can you should give a lot more credence to this answer).
'ac' going inside 'ball' is 'balacl'.
'balacl'+'ava'='BALACLAVA'
Can you help me to learn more?
(Other definitions for balaclava that I've seen before include "headwear" , "Crimean village; woollen hat" , "headgear" , "Warm hat" , "Close-fitting woollen head cover" .)