Incautious having wine and pork pie before run ... (8)
I believe the answer is:
cavalier
'incautious' is the definition.
(I've seen this before)
'wine and pork pie before run' is the wordplay.
'wine' becomes 'cava' (type of Spanish wine).
'and' says to put letters next to each other.
'pork pie' becomes 'lie' (I've seen this before).
'before' says to put letters next to each other.
'run' becomes 'r' (cricket abbreviation).
'cava'+'lie'+'r'='CAVALIER'
'having' acts as a link.
(Other definitions for cavalier that I've seen before include "Offhand - Charles I supporter" , "High-handed, supercilious" , "... King Charles, spaniel" , "Courtly gent - laughing in painting" , "Civil War participant" .)