We set out without a trace of bitterness (5)
I believe the answer is:
sweet
'bitterness' is the definition.
The answer and definition can be both human attributes as well as being singular nouns.
Perhaps there's a link between them I don't understand?
'we set out without a trace' is the wordplay.
'out' means to remove the last letter.
'without' means one lot of letters goes inside another.
'a trace' becomes 't' (this might be a standard abbreviation I've not previously seen).
'set' with its final letter taken away is 'se'.
'we' going within 'se' is 'swee'.
'swee'+'t'='SWEET'
'of' is the link.
Can you help me to learn more?
(Other definitions for sweet that I've seen before include "darling" , "Amiable" , "Sour companion" , "Sugary - but might be tart!" , "Pud" .)