Fairy host disguised in shrub (9)
I believe the answer is:
forsythia
'shrub' is the definition.
(forsythia is a kind of shrub)
'fairy host disguised' is the wordplay.
'disguised' indicates anagramming the letters.
'fairy'+'host'='fairyhost'
'fairyhost' anagrammed gives 'FORSYTHIA'.
'in' acts as a link.
(Other definitions for forsythia that I've seen before include "Say a frosty hi to the early blooming shrub with bright yellow flowers" , "Garden plant" , "bloomer in spring" , "A frosty hi to the flowering shrub" , "Ornamental shrub" .)