Rubbish bin's first put in car port (7)
I believe the answer is:
garbage
'rubbish' is the definition.
(thesaurus)
'bin's first put in car port' is the wordplay.
'first' suggests taking the first letters.
'put in' is an insertion indicator.
'car port' becomes 'garage' (I've seen this before).
The first letter of 'bins' is 'b'.
'b' inserted within 'garage' is 'GARBAGE'.
(Other definitions for garbage that I've seen before include "US rubbish" , "'Refuse, rubbish (7)'" , "Pop group; rubbish" , "Rubbish - invalid computer data" , "Brag about age? - that's rubbish" .)