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