Many-legged arthropod (9)
I believe the answer is:
centipede
'many-legged arthropod' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for centipede that I've seen before include "Many-legged arthropod" , "Multi-legged crawler" , "Many-legged creepy-crawly" , "Invertebrate with many legs" , "Myriapod" .)