Eat humble pie that a sport is dividing up, for example (9)
I believe the answer is:
apologise
'eat humble pie' is the definition.
I can't tell whether this definition defines the answer.
'a sport is dividing up for example' is the wordplay.
'sport' becomes 'polo' (polo is a kind of sport).
'dividing' indicates putting letters inside (inserted letters divide the word).
'up' is a reversal indicator (in down clue: letters go upwards).
'for example' becomes 'e.g.' (short for 'exempli gratia', 'for example' in Latin).
'eg' backwards is 'ge'.
'is' inserted inside 'ge' is 'gise'.
'a'+'polo'+'gise'='APOLOGISE'
'that' acts as a link.
Can you help me to learn more?
(Other definitions for apologise that I've seen before include "Recognise fault" , "Say sorry, my fault" , "Say one is sorry" , "Ask forgiveness" , "Acknowledge failings" .)