The lass going out without a bonnet? (7)
I believe the answer is:
hatless
'without a bonnet?' is the definition.
('bonnet' can be 'hat' (thesaurus) so maybe 'without a bonnet' can be ''hatless')
'the lass going out' is the wordplay.
'going out' indicates anagramming the letters (out can mean wrong or inaccurate).
'the'+'lass'='thelass'
'thelass' anagrammed gives 'HATLESS'.
(Other definitions for hatless that I've seen before include "Uncovered" , "Without a titfer" .)