Idle people, and what they step in (7)
I believe the answer is:
loafers
'what they step in' is the definition.
The definition suggests an adverb but the answer is not.
'idle people' is the wordplay.
'idle' becomes 'loaf' (loaf can mean to idle).
'people' becomes 'ers' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'loaf'+'ers'='LOAFERS'
'and' acts as a link.
Can you help me to learn more?
(Other definitions for loafers that I've seen before include "Casual shoes" , "Casual footwear" , "Comfortable shoes" , "They add cargo" , "couch potatoes" .)