Ball crossed by agile men onto level pitch (8)
I believe the answer is:
monotone
'pitch' is the definition.
(thesaurus)
'ball crossed by agile men onto level' is the wordplay.
I cannot really see how this works, but
'ball' could be 'o' (O looks like a ball) and 'o' is present in the answer.
an anagram of 'onto' is 'noto' which is within the answer.
an anagram of 'men' is 'mne' which is located in the remaining letters.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for monotone that I've seen before include "Single unvarying note" , "Utterance at a single unvaried level" , "Flat and unchanging in pitch" , "Single unvaried sound level" , "Sound of unvarying pitch" .)