Left, heading for Scotland after Wales, drunk and disorderly (7)
I believe the answer is:
lawless
'disorderly' is the definition.
(thesaurus)
'left heading for scotland after wales drunk' is the wordplay.
'left' becomes 'l' (common abbreviation**).
'heading for' suggests taking the first letters.
'after' says to put letters next to each other.
'drunk' is an anagram indicator.
The initial letter of 'scotland' is 's'.
'wales' with letters rearranged gives 'awles'.
's' after 'awles' is 'awless'.
'l'+'awless'='LAWLESS'
'and' is the link.
(Other definitions for lawless that I've seen before include "insubordinate" , "Anarchy" , "Ungoverned" , "Anarchic, without any controls" , "Unruly - anarchic" .)