Section representing advertisements (7)
I believe the answer is:
notices
'advertisements' is the definition.
(I've seen this before)
'section representing' is the wordplay.
'representing' indicates anagramming the letters (letters must be re-presented in a new way).
'section' is an anagram of 'NOTICES'.
(Other definitions for notices that I've seen before include "advertisements" , "Remarks upon publicly displayed informations" , "Perceives, sees" , "Section (anag) - spots" , "Discovers" .)