Tease the lad, dishevelled and dirty (6)
I believe the answer is:
ribald
'dirty' is the definition.
('ribald' can be similar in meaning to 'dirty')
'tease the lad dishevelled' is the wordplay.
'tease' becomes 'rib' (I've seen this before).
'dishevelled' is an anagram indicator.
'lad' with letters rearranged gives 'ald'.
'rib'+'ald'='RIBALD'
'and' acts as a link.
(Other definitions for ribald that I've seen before include "Licentious" , "Funny, but not nice" , "Humorous in vulgar or disrespectful way" , "Coarsely mocking" , "Irreverent" .)