It needs aid, we hear, to make a drink (5)
I believe the answer is:
lemon
This might be a double definition.
'it needs aid we hear' is the first definition.
The definition suggests a singular noun which matches the answer.
'a drink' is the second definition.
The definition and answer can be both things that one consumes for nourishment as well as being singular nouns.
Maybe there's a link between them I don't understand?
'to make' is the link.
Can you help me to learn more?
(Other definitions for lemon that I've seen before include "source of juice" , "Leaving body" , "something defective" , "Sharp-tasting fruit" , "stinker" .)