Center line on a stick figure (5)
I believe the answer is:
torso
'center line on a stick figure' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for torso that I've seen before include "Body without head, neck and limbs" , "Trunk of human body" , "Roost (anag)" , "Chest" , "Body, minus its head and limbs" .)