The Collaborative International Dictionary
Forbidding \For*bid"ding\, a. Repelling approach; repulsive; raising abhorrence, aversion, or dislike; disagreeable; prohibiting or interdicting; as, a forbidding aspect; a forbidding formality; a forbidding air.
Syn: Disagreeable; unpleasant; displeasing; offensive; repulsive; odious; abhorrent. -- For*bid"ding*ly, adv. -- For*bid"ding*ness, n.
Wiktionary
adv. in a forbidding manner
WordNet
adv. in an unpleasant or menacing manner; "it was forbiddingly dark in the corridor"
Usage examples of "forbiddingly".
So many of the most respected books of the last hundred years are so forbiddingly esoteric, syntactically dense, and formally complex, that they seem accessible only to the most dedicated and initiated readers.
Hulagh settled uneasily into his cushions in the rear of the landsled and saw it grow nearer: built of the soil of the mineral flats, cemented and dull-surfaced, it was of a color with the earth, but startling to the eye and forbiddingly sterile in its outlines.