Los Angeles, less than clean (7)
I believe the answer is:
launder
'clean' is the definition.
(laundering is a kind of cleaning)
'los angeles less than' is the wordplay.
'los angeles' becomes 'la'.
'less than' becomes 'under' (I've seen this before).
'la'+'under'='LAUNDER'
(Other definitions for launder that I've seen before include "Make clean again - clothes or money" , "Trough" , "Make illegal (money) legitimate" , "Make clean, clothing or money" , "Wash or cleanse, clothes or money" .)