A unit of land area in Thailand. The ngarn equals 1/4 rai, 100 talangwah (tw), or exactly 400 square meters (478.396 square yards or just under 0.1 acre)
Russ Rowlett (Director), How Many? A Dictionary of Units of Measurement, Center for Mathematics and Science Education University of North Carolina, USA 2005. http://www.unc.edu/~rowlett/units/dictA.html, (Unit of Meas and Covr Factors - Amer) {608}