A garden shrub Cilla ordered (5)
I believe the answer is:
lilac
'a garden shrub' is the definition.
'lilac' can be an answer for 'shrub' (lilac is a kind of shrub). I am unsure of the 'a garden' bit.
'cilla ordered' is the wordplay.
'ordered' indicates an anagram.
'cilla' with letters rearranged gives 'LILAC'.
Can you help me to learn more?
(Other definitions for lilac that I've seen before include "Spiritual knowledge" , "Lavender colour" , "Plant" , "Shrub with fragrant pink, purple or white flowers" , "Genus Syringa shrub" .)