Wind around southeast that's meant to strengthen (6)
I believe the answer is:
gusset
'meant to strengthen' is the definition.
I can't tell whether this defines the answer.
'wind around southeast' is the wordplay.
'wind' becomes 'gust' (gust is a kind of wind).
'around' means one lot of letters goes inside another.
'southeast' becomes 'SE' (synonyms).
'gust' placed around 'se' is 'GUSSET'.
'that's' is the link.
Can you help me to learn more?
(Other definitions for gusset that I've seen before include "Piece of inserted material" , "Piece inserted into garment for enlargement" , "Strengthening piece of fabric" , "Strengthening material insert" , "Garment enlarger" .)