2's flute, perhaps (5)
I believe the answer is:
glass
This clue could be a double definition.
'2's' is the first definition.
The definition and answer can be both quantities as well as being singular nouns.
Perhaps there's a link between them I don't understand?
'flute perhaps' is the second definition.
(I know that Western concert flute is a type of flute)
Can you help me to learn more?
(Other definitions for glass that I've seen before include "Watch-face cover" , "Perhaps schooner" , "Philip --, US composer" , "Telescope perhaps" , "Brittle transparent material" .)