What is "crith"

Crith \Crith\ (kr[i^]th), n. [Gr. kriqh` a barleycorn, a small weight.] (Chem.) The unit for estimating the weight of a[eum]riform substances; -- the weight of a liter of hydrogen at 0[deg] centigrade, and with a tension of 76 centimeters of mercury. It is 0.0896 of a gram, or 1.38274 grains.

n. (label en physics) the weight of 1 litre of hydrogen at standard temperature and pressure. Equal to approximately 0.09 grams.

n. the weight of a liter of hydrogen (at 0 Centigrade and 760 millimeters pressure)