Heaven usually reveals the morning star (5)
I believe the answer is:
'the morning star' is the definition.
(Venus was historically called the morning star)
'heaven usually reveals' is the wordplay.
'reveals' says the answer is hidden in the clue.
'VENUS' can be found hidden inside 'heaven usually'.
(Other definitions for venus that I've seen before include "Solar system planet" , "The embodiment of Love" , "One of the planets" , "Evening star" , "Morning star" .)