Holy hour initially permitted (8)
I believe the answer is:
hallowed
'holy' is the definition.
(synonyms)
'hour initially permitted' is the wordplay.
'initially' suggests taking the first letters.
'permitted' becomes 'allowed' ('allow' can be a synonym of 'permit').
The first letter of 'hour' is 'h'.
'h'+'allowed'='HALLOWED'
(Other definitions for hallowed that I've seen before include "Like saints" , "Held holy" , "Respected" , "Made blessed" , "Consecrated, blessed" .)