Shows humanity (4)
I believe the answer is:
errs
'shows humanity' is the definition.
The answer and definition can be both to do with motion as well as being verbs in their -s form.
Perhaps you can see a link between them that I can't see?
This is the entire clue.
Can you help me to learn more?
(Other definitions for errs that I've seen before include "Makes mistakes" , "Slips up" , "Goes wrong" , "Goes astray" , "Sins" .)