As a culinary device, it causes some friction (6)
I believe the answer is:
grater
'as' is the definition.
Although both the answer and definition are singular nouns, I don't understand how one could define the other.
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for grater that I've seen before include "Kitchen utensil" , "kitchen instrument" , "Kitchen device" , "Utensil for reducing to small particles" , "It makes small bits of food" .)