Look good on knight's arm (6)
I believe the answer is:
glance
'look' is the definition.
(I know that glance is a type of look)
'good on knight's arm' is the wordplay.
I cannot quite understand how this works, but
'good' could be 'g' (abbreviation) and 'g' is present in the answer.
'arm' could be 'lance' (lance is a kind of arm) and 'lance' is found in the answer.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for glance that I've seen before include "Swift look" , "Butcher" , "Glimpse" , "fly off" , "black shiny stuff" .)