unformidable

adjective

1. causing fear, apprehension, or dread: a formidable opponent.
2. of discouraging or awesome strength, size, difficulty, etc.; intimidating: a formidable problem.
3. arousing feelings of awe or admiration because of grandeur, strength, etc.
4. of great strength; forceful; powerful: formidable opposition to the proposal.

adjective

1. arousing or likely to inspire fear or dread
2. extremely difficult to defeat, overcome, manage, etca formidable problem
3. tending to inspire awe or admiration because of great size, strength, excellence, etc

adj.mid-15c., from Middle French formidable (15c.), from Latin formidabilis “causing fear, terrible,” from formidare “to fear,” from formido “fearfulness, fear, terror, dread.” Related: Formidably.