Look at the rage! (6)
I believe the answer is:
seethe
'rage' is the definition.
(I've seen this before)
'look at the' is the wordplay.
'look' becomes 'see'.
'at' says to put letters next to each other.
'see'+'the'='SEETHE'
(Other definitions for seethe that I've seen before include "Ferment, sizzle" , "Bubble as in boiling, or be very angry" , "Smoulder" , "Boil, be turbulent" , "froth" .)