Two-legged creature (5)
I believe the answer is:
biped
'two-legged creature' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for biped that I've seen before include "One walking on two feet" , "Two-legged animal" , "Eg man" , "Girl, say" , "Two-footed creature" .)