Definition of "nitrogenous"

The percentage of nutritive elements contained in the parsnip is very small; so small, indeed, that one pound of parsnips affords hardly one fifth of an ounce of nitrogenous or muscle-forming material.

1892, Ella Eaton Kellogg, “Vegetables”, in Science in the Kitchen: A Scientific Treatise on Food Substances and Their Dietetic Properties, Together with a Practical Explanation of the Principles of Healthful Cookery, and a Large Number of Original, Palatable, and Wholesome Recipes‎, Revised edition, Michigan: Health Publishing Company, page 243