threatening; menacing
Describes an attitude, action, or atmosphere that is intended to intimidate or convey a threat. Often used in formal or written contexts.
彼の威嚇的な態度に、周りの人は怖がっていた。
People around him were frightened by his threatening attitude.
その国は隣国に対して威嚇的な軍事演習を行った。
That country conducted menacing military exercises against its neighbor.
Formed from 威嚇 (intimidation) + 的 (-like, -ish). The exact historical derivation is uncertain, but the word follows a common pattern for creating adjectival nouns from nouns.