Style of metre poem follows (4)
I believe the answer is:
mode
'style' is the definition.
(I know that style can be written as mode)
'metre poem follows' is the wordplay.
'metre' becomes 'm' (synonyms).
'poem' becomes 'ode' (ode is a kind of poem).
'follows' is a charade indicator (letters next to each other).
'm'+'ode'='MODE'
'of' is the link.
(Other definitions for mode that I've seen before include "Way of operating" , "Style, method" , "Way, style" , "Fashion; way of performing" , "Way of doing something" .)