Popular signs, conspicuous (2,8)
I believe the answer is:
in evidence
'conspicuous' is the definition.
(similar in meaning)
'popular signs' is the wordplay.
'popular' becomes 'in' (something that's 'in' is fashionable).
'signs' becomes 'evidence' (I've seen this before).
'in'+'evidence'='IN EVIDENCE'
(Other definitions for in evidence that I've seen before include "how prisoner's statement may be used" , "Apparent" .)