Synonyms: redoubtable, unnerving, formidable
Definition: inspiring fear
Usage: 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 grey wall
Similar words: alarming
Definition: frightening because of an awareness of danger
Synonyms: formidable
Definition: extremely impressive in strength or excellence
Usage: 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
Similar words: impressive
Definition: making a strong or vivid impression
Usage: an impressive ceremony