Definition of gruffness:
severity (part of speech: noun)
And Rogers scowled a little as he thought of the air of gruffness he would assume while accepting it, saying as pleasantly as he could manage, 'Oh, Mr. Minks, that's nothing at all; I'm only too delighted to be of service to the lad.- "A Prisoner in Fairyland", Algernon Blackwood.
- "Laughing Bill Hyde and Other Stories", Rex Beach.
- "Miss Lulu Bett", Zona Gale.