Twerp, fool, horrid little weed lived by here (9)
I believe the answer is:
flowerpot
'little weed lived by here' is the definition.
Although both the answer and definition are singular nouns, I cannot see how they can define each other.
'twerp fool horrid' is the wordplay.
'horrid' indicates an anagram.
'twerp'+'fool'='twerpfool'
'twerpfool' is an anagram of 'FLOWERPOT'.
Can you help me to learn more?
(Other definitions for flowerpot that I've seen before include "Container for plants" , "Place for growing" , "Something grows in this" , "Geranium holder?" , "spotted on window-sill" .)