Large ugly royal (5)
I believe the answer is:
regal
'royal' is the definition.
(synonyms)
'large ugly' is the wordplay.
'ugly' indicates anagramming the letters (an ugly or wrong form of the letters).
'large' is an anagram of 'REGAL'.
(Other definitions for regal that I've seen before include "Magnificent, dignified" , "Portable organ" , "Royal - lager (anag)" , "fit for the Queen" , "'Majestic, royal (5)'" .)