Careless husband down with friends from the south (8)
I believe the answer is:
slapdash
'careless' is the definition.
(similar in meaning)
'husband down with friends from the south' is the wordplay.
'husband' becomes 'h' (abbreviation).
'down' becomes 'sad' (I've seen this in another clue).
'with' is a charade indicator (letters next to each other).
'friends' becomes 'pals' (pal is a kind of friend).
'from the south' shows that the letters should be reversed in order (in a down clue, letters go up).
'h'+'sad'+'pals'='hsadpals'
'hsadpals' written backwards gives 'SLAPDASH'.
(Other definitions for slapdash that I've seen before include "Hurried and careless" , "Slipshod, sloppy" , "Careless - haphazard" , "recklessly" , "Slipshod, careless" .)