Trendy to incline to be mean (6)
I believe the answer is:
intend
'be mean' is the definition.
(to intend to something is to mean it)
'trendy to incline' is the wordplay.
'trendy' becomes 'in' ('in' can mean fashionable).
'to incline' becomes 'tend' (synonyms).
'in'+'tend'='INTEND'
'to' acts as a link.
(Other definitions for intend that I've seen before include "Mean; aim" , "Mean; propose" , "Mean - purpose" , "Mean (to do something)" , "Aim, plan" .)