Milky Way? Yes and no (6)
I believe the answer is:
galaxy
'milky way?' is the definition.
(milky way is a kind of galaxy)
'yes and no' is the wordplay.
I cannot quite understand how this works, but
'yes' could be 'y' and 'y' is located in the answer.
The remaining letters 'galax' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for galaxy that I've seen before include "A large independent system of stars" , "Huge collection of stars" , "Milky Way, for instance" , "Astronomical system" , "Division of the universe" .)