For instance, good food for breakfast? (3)
I believe the answer is:
egg
'food for breakfast?' is the definition.
I can't tell whether this defines the answer.
'for instance good' is the wordplay.
'for instance' becomes 'eg' (short for 'exempli gratia', 'for example' in Latin).
'good' becomes 'g' (abbreviation).
'eg'+'g'='EGG'
Can you help me to learn more?
(Other definitions for egg that I've seen before include "Baby carrier?" , "Reproductive unit" , "Curate's good in parts" , "Source" , "Hen fruit" .)