[pes.tif.er.ous] adj [ME, fr. L pestifer pestilential, noxious, fr. pestis + -fer -ferous] (15c) 1: dangerous to society: pernicious
2. a: carrying or propagating infection: pestilential b: infected with a pestilential disease
3: troublesome, annoying -- pes.tif.er.ous.ly adv -- pes.tif.er.ous.ness n