Very penetrating remedy for wind (5)
I believe the answer is:
curve
'wind' is the definition.
(synonyms)
'very penetrating remedy' is the wordplay.
'very' becomes 'v' (abbreviation).
'penetrating' means one lot of letters goes inside another.
'remedy' becomes 'cure' (synonyms).
'v' going within 'cure' is 'CURVE'.
'for' is the link.
(Other definitions for curve that I've seen before include "Line on a graph" , "Gentle bend, arc" , "Line that's not straight" , "that may be hyperbolic" , "Line that isn't straight" .)