Fell, a. [OE. fel, OF. fel cruel, fierce, perfidious; cf. AS. fel (only in comp.) OF. fel, as a noun also accus. felon, is fr. LL. felo, of unknown origin; cf. Arm fall evil, Ir. feal, Arm. falloni treachery, Ir. & Gael. feall to betray; or cf. OHG. fillan to flay, torment, akin to E. fell skin. Cf. Felon.] 1. Cruel; barbarous; inhuman; fierce; savage; ravenous.
While we devise fell tortures for thy faults. Shak.
2. Eager; earnest; intent.
I am so fell to my business. Pepys.