Amateur seaman turned up for party (6)
I believe the answer is:
social
'for party' is the definition.
(social can mean a party or event)
'amateur seaman turned up' is the wordplay.
'amateur' becomes 'laic' (I can't explain this - if you can you should believe this answer much more).
'seaman' becomes 'OS' (short for ordinary seaman).
'turned up' says the letters should be written in reverse.
'laic'+'os'='laicos'
'laicos' written backwards gives 'SOCIAL'.
Can you help me to learn more?
(Other definitions for social that I've seen before include "Outgoing, extroverted" , "Liking companionship" , "Relating to living together in communities" , "Gregarious; a party" , "Cola is (anag) - companionable" .)