Green’s Dictionary of Slang

of a person, being aggressive and spoiling for a fight.

1843		Bellew Memoirs of a Griffin II 143: ‘Shak hands, ye fire-eating donard deevils ye’.
1843		Bellew Memoirs of a Griffin II 97: ‘Pass the bottle [...] fill up a bumper; come, a brimmer; no daylight, Sir’.
1854		G.J. Whyte-Melville General Bounce (1891) 176: Sir Ascot was none of your sighing, despairing, fire-eating adorers.
1863		N. Hawthorne Our Old Home 46: My fire-eating friend has had ample opportunities to banquet on his favorite diet .
1882		Nat. Police Gaz. (NY) 28 Oct. 7/3: [headline] | Fire-Eating Colonel Goes for Satisfaction and is Slain by a St Louis Editor.
1888		Nottingham Eve. Post 24 May 2/4: M. Leandri, a fire-eating editor from Bastia, has just arrived here for the purpose of challenging to mortal combat M. Lepelletier [...] who made some disparaging remarks about him.
1892		Sheffield Dly Teleg. 11 June 5/9: Fire-Eating Journalists. A duel is announced to take place to-day between two journalists.
1904		Sydney Sportsman (Surry Hills, NSW) 7 Dec. 3/3: [D]ear old fire-eating Sproozer bad been shamefully despoiled of that which is more prized by the man of 60 than his purse Itself .
1916		J. Buchan Greenmantle (1930) 135: My subalterns [...] were a lot of fire-eating young lunatics.
2000		M. Collins Keepers of Truth 29: Got a fire-eating wife that hates him.