Eleven on the shelf? (5)
I believe the answer is:
aside
'eleven on the shelf?' is the definition.
Although both the answer and definition are singular nouns, I don't understand how one could define the other.
'eleven on the shelf?' is the wordplay.
'eleven' becomes 'side' (a football side).
'on' is a charade indicator (letters next to each other).
'the shelf?' becomes 'a' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'side' after 'a' is 'ASIDE'.
Can you help me to learn more?
(Other definitions for aside that I've seen before include "In reserve; actor's remark to audience" , "(Pushed) out of the way" , "Quiet words spoken" , "secretly" , "Separately" .)