It's to one end of the foot (3)
I believe the answer is:
toe
'foot' is the definition.
(toeing is a kind of footing)
'it's to one end of the' is the wordplay.
'one end of' says to take the final letters.
The last letter of 'the' is 'e'.
'to'+'e'='TOE'
(Other definitions for toe that I've seen before include "Feature of footwear" , "Small member" , "one digit?" , "One's nailed" , "'Little piggy'" .)