Trendy seaside destination with no leader (5,2)
I believe the answer is:
right on
'trendy' is the definition.
(I've seen this before)
'seaside destination with no leader' is the wordplay.
'seaside destination' becomes 'brighton' (seaside resort).
'with no leader' means to remove the first letter.
'brighton' with its initial letter taken away is 'RIGHT-ON'.
(Other definitions for right on that I've seen before include "Fashionably liberal" , "Modern" , "Words of encouragement" , "Trendy and socially aware" , "Very PC - exclamation of agreement" .)