Thong? Ace bum’s out with it? (7,7)
I believe the answer is:
bathing costume
'thong? ace bum's out with it?' is the definition.
I can't judge whether this definition defines the answer.
'thong? ace bum's out with it?' is the wordplay.
'out with' indicates anagramming the letters (out can mean wrong or inaccurate).
'thong'+'ace'+'bums'='thongacebums'
'thongacebums' mixed up with 'it' makes 'BATHING COSTUME'.
Can you help me to learn more?
(Another definition for bathing costume that I've seen is " Something for the beach".)