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.
Grams Definition. The gram is a unit of mass. A gram is defined as one 1000 of the SI base unit the kilogram which itself is defined as being equal to the mass of a physical prototype preserved by the International Bureau of Weights and Measures.