Catching mum, keeping time after exercise (9)
I believe the answer is:
pestilent
'catching' is the definition.
Both the answer and definition are adjectives. Maybe they are linked in a way I don't understand?
'mum keeping time after exercise' is the wordplay.
'mum' becomes 'silent' (to keep mum can informally mean to stay silent).
'keeping' indicates putting letters inside.
'time' becomes 't' (abbreviation).
'after' means one lot of letters go next to another.
'exercise' becomes 'pe' (Physical Education).
'silent' enclosing 't' is 'stilent'.
'stilent' put after 'pe' is 'PESTILENT'.
Can you help me to learn more?
(Other definitions for pestilent that I've seen before include "Peel tints (anag) - extremely tiresome" , "Vexatious" , "Extremely harmful" , "Such a serious nuisance" , "Likely to spread epidemic disease" .)