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.
Official SI symbol. The only unit symbol for gram that is recognised by the International System of Units (SI) is g following the numeric value with a space, as in 640 g to stand for 640 grams in the English language.