Gossip has year to develop (7)
I believe the answer is:
hearsay
'gossip' is the definition.
(hearsay is a kind of gossip)
'has year to develop' is the wordplay.
'to develop' indicates anagramming the letters.
'has'+'year'='hasyear'
'hasyear' anagrammed gives 'HEARSAY'.
(Other definitions for hearsay that I've seen before include "Gossip or idle talk - it's not evidence" , "rumoured" , "Gossip passed around by word of mouth" , "Gossip or rumour - not allowed as evidence" , "speculation" .)