Looking round for a letter? (8)
I believe the answer is:
This clue could be a double definition.
'looking round' is the first definition.
'circular' can be an answer for 'round' (I've seen this before). I'm not certain of the 'looking' bit.
'for a letter?' is the second definition.
(type of advertisement)
Can you help me to learn more?
(Other definitions for circular that I've seen before include "Letter or notice copied to a number of people" , "Round; general letter" , "Widely-distributed notice" , "Spherical" , "Perfectly round" .)