Green’s Dictionary of Slang

at least, more than, e.g. easily twenty.

1936		T. O’Reilly Tiger of the Legion v: At fifty-two Mr. O’Reilly looks easily seventy-five.
1971		R.T. Sale Blackstone Rangers 67: ‘Well, like he’s been shot at least eight times [...] Easily that many’.
2003		Wash. Post 18 Mar. 🌐 For despite a fine performance and the requisite gray coloring in his dark hair, Morella is easily 20 years too young for the part.