Revealing or having little emotion or sensibility; impassive; unemotional.
The Indian sat on the front seat, saying nothing to anybody, with a stolid expression of face, as if barely awake to what was going on. Again I was struck by the peculiar vagueness of his replies when addressed in the stage, or at the taverns. He really never said anything on such occasions. He was merely stirred up, like a wild beast, and passively muttered some insignificant response. His answer, in such cases, was never the consequence of a positive mental energy, but vague as a puff of smoke, suggesting no responsibility, and if you considered it, you would find that you had got nothing out of him. This was instead of the conventional palaver and smartness of the white man, and equally profitable.
—Henry David Thoreau “The Allegash and East Branch” The Maine Woods (1864) The Writings of Henry David Thoreau (1906)