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rian

In Ceylon (Sri Lanka), at least as early as the 17ᵗʰ century – ?, two units of length:

A Rian is a Cubit, which is with them from the bone on the inside of the Elbow to the tip of the fourth Finger. A Waddo rian is the Carpenters Rule. It is as much as will reach from one Elbow to the other, the Thumbs touching one the other at the tops, and so stretching out both Elbows.

Robert Knox.
An Historical Relation of the Island of Ceylon, in the East-Indies: together with an Account of the Detaining in Captivity the Author and divers other Englishmen now Living there, and of the Author's Miraculous Escape.
London: Richard Chiswell, 1681.
Page 98.