Looking for loose change, sir? (9)
I believe the answer is:
searching
'looking for' is the definition.
('search' can be a synonym of 'look for')
'loose change sir?' is the wordplay.
'loose' indicates anagramming the letters (letters are loosened from their original positions).
'change'+'sir'='changesir'
'changesir' with letters rearranged gives 'SEARCHING'.
(Other definitions for searching that I've seen before include "Hunting (for)" , "Going through" , "Exploring" .)