A warning signal (such as the call of sentry, the ringing of a bell, or the shriek of a siren) which turns out to have been given erroneously.
A thing or occurrence which initially causes fear, distress, etc. but which is subsequently recognized as being no cause for concern.
An error; a blunder.
A pitch which was intended to be pitched in a hard-to-hit location, but instead ends up in an easy-to-hit place.
To understand wrongly, taking one thing or person for another.