formidable
I
adjective
alarming, appalling, arduous, awe-inspiring, awesome, dangerous, deterring, difficult, disturbing, dreadful, exciting fear, fear-inspiring, fearful, fierce, formidolosus, frightening, frightful, hard to overcome, horrible, horrifying, huge, indomitable, menacing, overpowering, overwhelming, redoubtable, terrible, terrifying, threatening, unconquerable, unnerving, unyielding
II
index
important (significant), indomitable, inexpugnable, insuperable, insurmountable, irresistible, onerous, operose, oppressive, potent, spartan, strong, unapproachable
Burton's Legal Thesaurus.
William C. Burton.
2006