: an event or act which shows that something exists or that gives information about something
: something (such as a sound, a movement of part of the body, or an object) that gives information about something or that tells someone to do something
: a piece of equipment with colored lights that is used on railways and roads to tell people when to go, to slow down, or to stop
: to be a sign of (something) : to show the existence of (something)
: to make a sound or motion that tells someone something
: very important or great
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