Intimidatingly impressive; awe-inspiring, overwhelming.
Appearing to be difficult; challenging.
Discouraging; inspiring fear.
The act of defeating, overcoming, or overwhelming.
The act of discouraging or intimidating; discouragement, intimidation.
Genuinely horrific, awful, or alarming.
Unpleasant, dreadful, awful (also used as an intensifier).
Frightfully; very.