Homework over some food: tongue (7)
I believe the answer is:
yiddish
'tongue' is the definition.
(Yiddish is an example)
'homework over some food' is the wordplay.
'homework' becomes 'diy' (DIY is work done on your home).
'over' is a reversal indicator.
'some food' becomes 'dish' (dish is a kind of food).
'diy' back-to-front is 'yid'.
'yid'+'dish'='YIDDISH'
(Other definitions for yiddish that I've seen before include "Hebrew-based language" , "European Jewish vernacular" , "Mixed language used by Jews of central and eastern Europe" , "Old Jewish language" , "Language spoken by Jews" .)