Raised to the third power (5)
I believe the answer is:
'raised to the third power' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for cubed that I've seen before include "One is so unchanging" , "(Of number) multiplied by its own square" , "Like some sugar" , "Diced - raised to the third power" , "To the power of three" .)