Bill's partner has carried peer around a US state (8)
I believe the answer is:
colorado
'us state' is the definition.
(I've seen this before)
'bill's partner has carried peer around a' is the wordplay.
'bill's partner' becomes 'coo' (I've seen this in another clue).
'has' means one lot of letters goes inside another.
'carried peer' becomes 'lord' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'around' is an insertion indicator.
'lord' enclosing 'a' is 'lorad'.
'coo' placed around 'lorad' is 'COLORADO'.
Can you help me to learn more?
(Other definitions for colorado that I've seen before include "Beetle whose larvae destroy potato plants" , "Boulder's state" , "Denver's state" , "US state in the Rocky Mountains" , "US state, W. of Kansas" .)