Garden weed endangered hosts (4)
I believe the answer is:
eden
'garden' is the definition.
(Garden of Eden in the Bible)
'weed endangered hosts' is the wordplay.
'hosts' says the answer is hidden in the clue.
'EDEN' is hidden within 'weed endangered'.
(Other definitions for eden that I've seen before include "The most enchanting garden of all" , "The best of all gardens" , "Place of unspoiled beauty" , "Early garden - Cornish project" , "River - garden" .)