Fungus — a lot stood all around (9)
I believe the answer is:
toadstool
'fungus' is the definition.
(toadstool is a kind of fungus)
'a lot stood all around' is the wordplay.
'all around' indicates anagramming the letters.
'a'+'lot'+'stood'='alotstood'
'alotstood' is an anagram of 'TOADSTOOL'.
(Other definitions for toadstool that I've seen before include "Common fungus" , "a potentially toxic development" , "what's poisonous maybe" , "Support for little people" , "Umbrella-shaped cap on a stalk" .)