Allocate grand in passing, without setting limits (6)
I believe the answer is:
assign
'allocate' is the definition.
(I've seen this in another clue)
'grand in passing without setting limits' is the wordplay.
'grand' becomes 'g' (G is short for grand as in a thousand).
'in' means one lot of letters goes inside another.
'without setting limits' means to look at the middle letters (the limits of the word are removed).
The middle of 'passing' is 'assin'.
'g' going within 'assin' is 'ASSIGN'.
(Other definitions for assign that I've seen before include "share out" , "(Of a job) allocate to someone" , "Attribute" , "Transfer property" , "Allocate or transfer" .)