All mice out to eat a shrub (8)
I believe the answer is:
camellia
'shrub' is the definition.
(I know that camellia is a type of shrub)
'all mice out to eat a' is the wordplay.
'out' indicates anagramming the letters (out can mean wrong or inaccurate).
'to eat' is an insertion indicator.
'all'+'mice'='allmice'
'allmice' is an anagram of 'cmellia'.
'cmellia' enclosing 'a' is 'CAMELLIA'.
(Other definitions for camellia that I've seen before include "Flowering shrub for Mal and Celia, oddly" , "Ornamental shrub with rose-like flowers" , "Claim ale from the flowering shrub" , "10" , "Blooming" .)