Exercises lithe cats become involved in (9)
I believe the answer is:
athletics
'involved in' is the definition.
Although both the answer and definition are singular nouns, I cannot see how they can define each other.
'exercises lithe cats' is the wordplay.
'exercises' indicates an anagram (letters exercise or move around).
'lithe'+'cats'='lithecats'
'lithecats' is an anagram of 'ATHLETICS'.
'become' acts as a link.
Can you help me to learn more?
(Other definitions for athletics that I've seen before include "Sports -- cheat list (anag)" , "Lithe acts observed in sporting contests" , "Sports - his cattle (anag)" , "Lithe acts performed in physical sports" , "Physical sports for trained competitors" .)