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.
It has many definitions, but the most known of them is equal to 454 metric grams. Gram (abbr. g) is a widely-spread unit of mass from the International System of Units. One kilogram, which is the basin unit of the ISU, has 1000 grams. The International System of Units (abbr. ISU, SI) is a modern system of measurement units, which is most widely used in the world. In consists of seven basic units: meters, kilograms, ampere, second, kelvin, mole, and candela).