Mark somewhere to find half-digested food? (9)
I believe the answer is:
semicolon
'mark somewhere' is the definition.
'semicolon' can be an answer for 'mark' (I've seen this before). I'm unsure of the 'somewhere' bit.
'half-digested food?' is the wordplay.
'half' becomes 'semi' (I've seen this before).
'digested food?' becomes 'colon' (I can't justify this - if you can you should give a lot more credence to this answer).
'semi'+'colon'='SEMICOLON'
'to find' is the link.
Can you help me to learn more?
(Other definitions for semicolon that I've seen before include "used by writers for a break" , "Item of punctuation" , "Punctuation mark denoting a pause in a sentence" , "half a stop" , "can cut sentence" .)