Amusing to take part in exercising, but no runs (12)
I believe the answer is:
entertaining
'amusing' is the definition.
(similar in meaning)
'part in exercising but no runs' is the wordplay.
'part in' becomes 'enter' (I can't explain this - if you can you should believe this answer much more).
'exercising' becomes 'training' (training is a kind of exercising).
'but no' is a deletion indicator.
'runs' becomes 'r' (cricket abbreviation).
'training' with 'r' taken out is 'taining'.
'enter'+'taining'='ENTERTAINING'
'to take' acts as a link.
Can you help me to learn more?
(Other definitions for entertaining that I've seen before include "creating a diversion" , "At home" , "Comical" , "Delightful" , "Recreational" .)