Exciting fear or apprehension; impressing dread; adapted to excite fear and deter from approach, encounter, or undertaking; alarming
Johnston; "something unnerving and prisonlike about high gray wall" extremely impressive in strength or excellence; "a formidable opponent"; "the challenge was formidable"; "had a formidable array of compositions to his credit"; "the formidable army of brains at the Prime Minister's disposal
extremely impressive in strength or excellence; "a formidable opponent"; "the challenge was formidable"; "had a formidable array of compositions to his credit"; "the formidable army of brains at the Prime Minister's disposal
inspiring fear; "the formidable prospect of major surgery"; "a tougher and more redoubtable adversary than the heel-clicking, jackbooted fanatic"- G H Johnston; "something unnerving and prisonlike about high gray wall"
causing fear, dread, awe or admiration as a result of size, strength, or some other impressive quality; commanding respect
If you describe something or someone as formidable, you mean that you feel slightly frightened by them because they are very great or impressive. We have a formidable task ahead of us Marsalis has a formidable reputation in both jazz and classical music
inspiring fear; "the formidable prospect of major surgery"; "a tougher and more redoubtable adversary than the heel-clicking, jackbooted fanatic"- G