Two chaps run out (7)
I believe the answer is:
petered
'run out' is the definition.
The answer and definition are different parts of speech. However, past participle verbs and adjectives can sometimes define each other.
'two chaps' is the wordplay.
'two chaps' can mean two substitutions for 'chap'.
'chap' becomes 'peter' (Peter is a man's name).
'chap' becomes 'Ed' (short for Edward).
'peter'+'ed'='PETERED'
Can you help me to learn more?
(Another definition for petered that I've seen is " exhausted".)