Starch from certain palms (4)
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
sago
(Other definitions for sago that I've seen before include "Powdery starchy food" , "Type of milk pudding" , "Powdery starch used in cooking" , "Starchy cereal used in puddings" , "Edible powdery starch" .)