Goddess sacrificing hearts in time (3)
I believe the answer is:
era
'time' is the definition.
(I know that era is a type of geologic time)
'goddess sacrificing hearts' is the wordplay.
'goddess' becomes 'Hera' (Greek goddess).
'sacrificing' indicates named letters should be taken away.
'hearts' becomes 'h' (abbreviation used in card games e.g. bridge).
'hera' with 'h' taken away is 'ERA'.
'in' acts as a link.
(Other definitions for era that I've seen before include "Geological age" , "Long period of history" , "Eon" , "Long period of time" , "Significant time" .)