The south wind heading east looks serious (7)
I believe the answer is:
austere
'serious' is the definition.
(I've seen this before)
'the south wind heading east' is the wordplay.
'the south wind' becomes 'auster' (I've seen this in another clue).
'heading east' becomes 'e' (abbreviation).
'auster'+'e'='AUSTERE'
'looks' acts as a link.
I am not very happy about this link. It may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for austere that I've seen before include "Hard" , "Strict in appearance" , "Lacking adornments" , "Abstemious, strict" , "Stern, grave" .)