Men elope, running by lake for zest (5,4)
I believe the answer is:
lemon peel
'zest' is the definition.
(I've seen this before)
'men elope running by lake' is the wordplay.
'running' is an anagram indicator (the letters run around to different places).
'by' is a charade indicator (letters next to each other).
'lake' becomes 'L' (geographical abbreviation).
'men'+'elope'='menelope'
'menelope' is an anagram of 'lemonpee'.
'lemonpee'+'l'='LEMON PEEL'
'for' acts as a link.
(Other definitions for lemon peel that I've seen before include "twist" , "Source of zest" .)