Forbidding, 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.
Shades of meaning
Fernald lists forbidding only as an antonym, under pleasant, propitious.
He lists it without comment; the entries above explain its neighbors.
Synonyms
none given