ஓர் அங்குலம் - An inch.
விரற்கடை. - Finger end or finger breadth.
NOTE:- The approximate value of 1 Angulam = 82 of an English inch. 12 angulams = 1 span (சாண்). There are many ways of measuring an Angulam, but it generally means ½ of the circumference of the 2nd joint of the thumb. It also comes to mean the 12th of anything.