Right-angle shape (3)
I believe the answer is:
ell
'right-angle shape' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for ell that I've seen before include "Former textile measure" , "Old measure of length about 45 inches" , "Embellish with old measure of length" , "distance" , "approximately 45 inches" .)