For Lily a special house key (8)
I believe the answer is:
asphodel
'for lily' is the definition.
(type of lily)
'a special house key' is the wordplay.
'special' becomes 'sp' (abbreviation).
'house' becomes 'ho' (abbreviation for house).
'key' becomes 'del' (del key on a keyboard).
'a'+'sp'+'ho'+'del'='ASPHODEL'
(Other definitions for asphodel that I've seen before include "Shop deal (anag.)" , "Mediterranean plant" , "Elysian plant" , "Lad hopes (anag) - flower" , "Old shape (anag) - plant" .)