Demure fashions – start of trend (6)
I believe the answer is:
modest
'demure' is the definition.
(similar in meaning)
'fashions start of trend' is the wordplay.
'fashions' becomes 'modes' ('mode' can be a synonym of 'fashion').
'start of' suggests taking the first letters.
The initial letter of 'trend' is 't'.
'modes'+'t'='MODEST'
(Other definitions for modest that I've seen before include "Unostentatious" , "Avoiding indecency; unassuming" , "Not vain, rather shy" , "Simple, humble" , "Unassuming or decent" .)