Allocate American bum home with grand interior (6)
I believe the answer is:
assign
'allocate american' is the definition.
'assign' can be an answer for 'allocate' (I've seen this in another clue). I am unsure of the 'american' bit.
'bum home with grand interior' is the wordplay.
'bum' becomes 'ass' (synonyms).
'home' becomes 'in' (to be in is to be (at) home).
'with' means one lot of letters go next to another.
'grand' becomes 'g' (G is short for grand as in a thousand).
'interior' is an insertion indicator.
'ass'+'in'='assin'
'assin' enclosing 'g' is 'ASSIGN'.
Can you help me to learn more?
(Other definitions for assign that I've seen before include "Allot or ascribe" , "Delegate" , "Transfer or appoint to" , "share out" , "Set aside for a specific purpose" .)