May suggest milk, but you can do it in water (5)
I believe the answer is:
float
'may' is the definition.
The answer and definition can be both related to time as well as being singular nouns.
Maybe there's an association between them I don't understand?
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for float that I've seen before include "Be buoyant" , "bread supply?" , "Levitate" , "Rest on liquid" , "Rest on the surface of a fluid" .)