Royal glare that's malicious (5)
I believe the answer is:
regal
'royal' is the definition.
(I know that royal can be written as regal)
'glare that's malicious' is the wordplay.
'that's malicious' indicates an anagram.
'glare' with letters rearranged gives 'REGAL'.
(Other definitions for regal that I've seen before include "Kingly glare?" , "King's" , "Showing great dignity" , "Magnificent, dignified" , "Kingly or queenly" .)