Glance shows a number in fault (7)
I believe the answer is:
deflect
'glance' is the definition.
The answer and definition can be both to do with motion as well as being verbs in their base form.
Perhaps they are linked in a way I don't understand?
'shows a number in fault' is the wordplay.
'shows a number' becomes 'l' (I can't justify this - if you can you should believe this answer much more).
'in' means one lot of letters goes inside another.
'fault' becomes 'defect' (synonyms).
'l' put within 'defect' is 'DEFLECT'.
Can you help me to learn more?
(Other definitions for deflect that I've seen before include "Change course" , "Parry, turn aside" , "Swerve" , "Cause to go off course" , "Turn aside or deviate from course." .)