Rigor is something strict, severe or demanding. 1  Harsh and strict treatment in the military for cadets is an example of rigor. 2  Freezing weather and ice are examples of the rigors of winter.  Difficult and challenging academic courses are an example of academic rigor.
The suffix gram means to draw or write. This is used in telegram.
Etymology: L, gramma, small weight. a unit of mass in the metric system equal to 1/1000 kilogram, 15.432 grains, and 0.0353 ounce avoirdupois. 453.6 g = 1 lb. The preferred abbreviation is g.