Written verses regularly seen in Spectator (7)
I believe the answer is:
witness
'spectator' is the definition.
(synonyms)
'written verses regularly seen' is the wordplay.
'regularly seen' means one should take alternating letters.
'written'+'verses'='writtenverses'
The alternate letters of 'writtenverses' are 'WITNESS'.
'in' is the link.
(Other definitions for witness that I've seen before include "Onlooker" , "Attest" , "See (an event or crime)" , "It's news (anag.)" , "Bystander" .)