A young lady that's out of order (5)
I believe the answer is:
amiss
'out of order' is the definition.
('amiss' can be a synonym of 'out of order')
'a young lady' is the wordplay.
'young lady' becomes 'miss' ('miss' can be a synonym of 'young lady'**).
'a'+'miss'='AMISS'
'that's' acts as a link.
(Other definitions for amiss that I've seen before include "Mistaken" , "Out of order" , "inappropriately" , "Taking wrong turn" , "Not quite right" .)