After exercise, lady in bad mood (5)
I believe the answer is:
peeve
'after exercise lady in bad mood' is the definition.
I can't tell whether this defines the answer.
'after exercise lady' is the wordplay.
'after' means one lot of letters go next to another.
'exercise' becomes 'pe' (Physical Education).
'lady' becomes 'eve' (I've seen this before).
'pe' next to 'eve' is 'PEEVE'.
Can you help me to learn more?
(Other definitions for peeve that I've seen before include "upset" , "cause irritation" , "Cause to be annoyed, irritated, or resentful" , "Vex" , "Intensely annoy" .)