Drop round for starchy cereal (4)
I believe the answer is:
sago
'starchy cereal' is the definition.
(I've seen this before)
'drop round' is the wordplay.
'drop' becomes 'sag' (sagging is a kind of dropping).
'round' becomes 'o' (round can mean a round object).
'sag'+'o'='SAGO'
'for' acts as a link.
(Other definitions for sago that I've seen before include "dessert?" , "Cereal, used in pudding" , "Starchy cereal used in puddings" , "Powdery starch used in cooking" , "Palm cereal" .)