Definition of "fiercely"

They burned the old gun that used to stand in the dark corner up in the garret, close to the stuffed fox that always grinned so fiercely. Perhaps the reason why he seemed in such a ghastly rage was that he did not come by his death fairly. And why else was he put away up there out of sight?—and so magnificent a brush as he had too.

1879, R[ichard] J[efferies], chapter 1, in The Amateur Poacher, London: Smith, Elder, & Co., […]

He helped himself to a cigar and leaned back with a fiercely critical pair of eyes, taking note of the effect which this document would produce.

1912, Arthur Conan Doyle, The Lost World […], London, New York, N.Y.: Hodder and Stoughton

Tuchel made it three out of three against Guardiola by producing a fiercely disciplined, positive Chelsea performance that has brought a season that was shrouded in uncertainty to the most glorious conclusion.

2021 May 29, Phil McNulty, “Manchester City 0-1 Chelsea”, in BBC Sport‎