na-adjective
menacing; threatening
Describes a manner, attitude, or atmosphere that feels intimidating or coercive, often implying psychological pressure.
彼の口調は脅迫的だった。
His tone was threatening.
脅迫的な態度を取るのはやめてください。
Please stop taking a menacing attitude.
脅す is a verb meaning 'to threaten'; 脅迫的 is an adjective describing the nature of an action or atmosphere.
Formed from 脅迫 (intimidation, threat) + 的 (-like, -ish), a common pattern for creating adjectival nouns.