Fetching details from the dictionary...
blackmail; extortion; threat (to extort money)
彼は恐喝の容疑で逮捕された。
He was arrested on suspicion of blackmail.
恐喝を受けたらすぐ警察に届けるべきだ。
If you're being blackmailed, report to the police immediately.
恐喝未遂でも処罰の対象となる。
Even attempted blackmail is subject to punishment.