a. [ L. formidabilis, fr. formidare to fear, dread: cf. F. formidable. ] Exciting fear or apprehension; impressing dread; adapted to excite fear and deter from approach, encounter, or undertaking; alarming. [ 1913 Webster ]
They seemed to fear the formodable sight. Dryden. [ 1913 Webster ]
I swell my preface into a volume, and make it formidable, when you see so many pages behind. Drydn.
n. The quality of being formidable, or adapted to excite dread. Boyle. [ 1913 Webster ]
a. [ L. informidabilis. See In- not, and Formidable. ] Not formidable; not to be feared or dreaded. [ Obs. ] “Foe not informidable.” Milton. [ 1913 Webster ]