Encara no tenim significats per a "be a gruffness".
1There was a gruffness in the invitation which under ordinary circumstances would have repelled a visitor.
2There was a gruffness in Jerry's voice as he answered, a gruffness that tried hard to mask the trembling of his tones.
3"And that will be one favor owed." There was a gruffness in his voice and a sly glint in his eye.