FELONIOUS Meaning of FELONIOUS in English [fe.lo.ni.ous] adj (1575) 1 archaic: very evil: villainous 2: of, relating to, or having the nature of a felony -- fe.lo.ni.ous.ly adv -- fe.lo.ni.ous.ness n Merriam-Webster English vocab. Английский словарь Merriam Webster. 2012