Blithe and hirsute cockney (4)
I believe the answer is:
airy
I believe this is a double definition.
'blithe' is the first definition.
(I've seen this in another clue)
'hirsute cockney' is the second definition.
('hairy' - synonyms - said with the 'H' dropped - a cockney accent.)
'and' acts as a link.
(Other definitions for airy that I've seen before include "Sprightly" , "Well-ventilated; delicate" , "Ethereal" , "(Of ideas) speculative" , "Flippant" .)