Period of fasting before Easter (4)
I believe the answer is:
lent
'period of fasting before easter' is the definition.
(Christian fast leading up to Easter)
This is the entire clue.
(Other definitions for lent that I've seen before include "Gave for a limited period" , "Gave the use of for a time" , "Fast time" , "Loaned; a fast" , "From Ash Wednesday to Holy Saturday" .)