Heard to start race for ingredient (4)
I believe the answer is:
sago
'race for ingredient' is the definition.
Although both the answer and definition are singular nouns, I can't understand how they can define each other.
'heard to start' is the wordplay.
'heard' becomes 'sa' (I can't justify this - if you can you should give a lot more credence to this answer).
'to start' becomes 'go' ('go' can be a synonym of 'start').
'sa'+'go'='SAGO'
Can you help me to learn more?
(Other definitions for sago that I've seen before include "Starchy cereal used in puddings" , "Edible powdery starch" , "Cereal, used in pudding" , "Starchy pudding cereal" , "Starchy grain used in desserts" .)