Definition of "grossest"

It would be some advantage to live a primitive and frontier life, though in the midst of an outward civilisation, if only to learn what are the gross necessaries of life and what methods have been taken to obtain them; or even to look over the old day-books of the merchants, to see what it was that the men most commonly bought at the stores, what they stored, that is, what are the grossest groceries.

1854, Henry David Thoreau, Walden (1886 republication), chapter 1: “Economy”, page 10