Strange footnote: 'Tree from which this produce is derived (4,5)
I believe the answer is:
rump steak
'which this produce is derived' is the definition.
The answer and definition can be both things that one consumes for nourishment as well as being singular nouns.
Perhaps there's a link between them I don't understand?
'strange footnote 'tree' is the wordplay.
'strange' becomes 'rum' (synonyms).
'footnote' becomes 'PS'.
''tree' becomes 'teak' (teak is a kind of tree).
'rum'+'ps'+'teak'='RUMP STEAK'
'from' acts as a link.
Can you help me to learn more?
(Other definitions for rump steak that I've seen before include "might be something for the barbecue" , "Meat" , "Cut of beef" .)