To be very severely scared or worried. Hyperbolically alludes to having been frightened so badly as to have died from it. I was frightened to death when I thought I heard footsteps on the staircase when no one else was home. We were frightened to death when we woke up to the sound of the howler monkeys. We had no idea what it was coming from. I'm frightened to death that the tests are going to come back positive.