Epoch Heracles embodies (3)
I believe the answer is:
era
'epoch' is the definition.
(I know that epoch can be written as era)
'heracles embodies' is the wordplay.
'embodies' indicates a hidden word.
'ERA' is hidden in the letters of 'heracles'.
(Other definitions for era that I've seen before include "Period, age" , "Specific time" , "Epoch, period" , "Stage" , "Memorable period" .)