To threaten or menace someone (by words or actions) in order to intimidate them or force them to do something.
彼は借金を返さないと殺すと脅した。
He threatened to kill him if he didn't repay the loan.
店内で客を脅して金を取るようなことは許されない。
It's unacceptable to threaten customers in a store to take their money.
脅すつもりはなかったが、言い方がきつくなってしまった。
I didn't mean to threaten him, but my tone ended up sounding harsh.