Read quickly; type of milk (4)
I believe the answer is:
skim
I believe this is a double definition.
'read quickly' is the first definition.
(I've seen this in another clue)
'type of milk' is the second definition.
(I've seen this in another clue)
(Other definitions for skim that I've seen before include "avoid paying income tax" , "Pass swiftly and lightly over the surface" , "Remove top layer; read bits of" , "Read superficially" , "Read (something) quickly" .)