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.
The gram (abbreviation and symbol: g) is the unit of mass in the metric system (SI, International System of Units). 1 gram (g) = 1000 milligrams (mg) = 0.001 kilogram (kg) = 0.0352739619 ounces (oz) = 0.00220462262 pounds (lbs) = 0.000157473044 stones (st).