Chuck is of unusual worth (5)
I believe the answer is:
throw
'chuck' is the definition.
(I've seen this before)
'of unusual worth' is the wordplay.
'of unusual' indicates anagramming the letters (I've seen 'unusual' mean this).
'worth' is an anagram of 'THROW'.
'is' acts as a link.
(Other definitions for throw that I've seen before include "Cast, lob" , "Project through the air" , "Cast, fling" , "Dumbfound" , "Cast; give (party)" .)