Worthless, it may come to us free (6)
I believe the answer is:
refuse
'worthless it' is the definition.
I can't judge whether this defines the answer.
'may come to us free' is the wordplay.
'may come to' indicates an anagram.
'us'+'free'='usfree'
'usfree' is an anagram of 'REFUSE'.
Can you help me to learn more?
(Other definitions for refuse that I've seen before include "Trash" , "Reject the waste material" , "Decline to jump; rubbish" , "Decline to accept garbage" , "Decline waste material" .)