Unusually large or majestic (5)
I believe the answer is:
regal
'majestic' is the definition.
(I know that majestic can be written as regal)
'unusually large' is the wordplay.
'unusually' indicates anagramming the letters.
'large' with letters rearranged gives 'REGAL'.
'or' is the link.
(Other definitions for regal that I've seen before include "Royal - 5 down (anag)" , "Showing great dignity" , "Kingly or queenly" , "King-like" , "Befitting a monarch" .)