Wide-brimmed hat for solemn occasion, initially (8)
I believe the answer is:
sombrero
'wide-brimmed hat' is the definition.
(I've seen this in another clue)
'solemn occasion initially' is the wordplay.
'solemn' becomes 'sombre' (synonyms).
'occasion initially' becomes 'ro' (I can't justify this - if you can you should give a lot more credence to this answer).
'sombre'+'ro'='SOMBRERO'
'for' is the link.
Can you help me to learn more?
(Other definitions for sombrero that I've seen before include "Mexican's hat" , "Rob Morse of his strange hat" , "Wide-brimmed hat of Mexico" , "It may be felt" , "a Mexican's overheads" .)