Wept bitterly, about to come back for alloy (6)
I believe the answer is:
pewter
'for alloy' is the definition.
(pewter is a kind of alloy)
'wept bitterly about to come back' is the wordplay.
I cannot really understand how this works, but
an anagram of 'wept' is 'pewt' which is present in the answer.
The remaining letters 'er' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for pewter that I've seen before include "Alloy of tin and lead, often in beer mug" , "Tin/copper (utensils)" , "An alloy of tin with a small amount of other metal" , "Alloy mainly of tin and lead" , "Plate" .)