Spoil one occasion near the sea (8)
I believe the answer is:
maritime
'sea' is the definition.
Both the definition and answer are adjectives. Perhaps you can see an association between them that I can't see?
'spoil one occasion near' is the wordplay.
'spoil' becomes 'mar' (synonyms).
'one' becomes 'i' (Roman numeral).
'occasion' becomes 'time' (I've seen this in another clue).
'near' is a charade indicator (letters next to each other).
'mar'+'i'+'time'='MARITIME'
'the' is the link.
Can you help me to learn more?
(Other definitions for maritime that I've seen before include "Found near the sea" , "Of seafaring or shipping" , "Nautical" , "Bordering on the sea" , "Relating to the sea" .)