She's a bit mad in the morning (5)
I believe the answer is:
madam
'she's a bit' is the definition.
I can't judge whether this defines the answer.
'mad in the morning' is the wordplay.
'in the morning' becomes 'am' (short for ante meridiem - before noon).
'mad'+'am'='MADAM'
Can you help me to learn more?
(Other definitions for madam that I've seen before include "Make wildly happy" , "Formal address to a woman - precocious little girl" , "Bossy girl" , "What you would call a female customer (or a spoiled girl!)" , "Courteous form of address to a woman" .)