Demure fashions – start of trend (6)
I believe the answer is:
modest
'demure' is the definition.
(similar in meaning)
'fashions aeur start of trend' is the wordplay.
I cannot really see how this works, but
'fashions' could be 'modes' ('mode' can be a synonym of 'fashion') and 'modes' is found within the answer.
A single letter 't' remains which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for modest that I've seen before include "Simple, humble" , "'Humble, unassuming (6)'" , "Not vain, rather shy" , "Lacking vanity" , "Not conceited, unassuming" .)