signal
noun
anything that serves to indicate, warn, direct, command, or the like, such as a light, a gesture, an act, etc.: a signal to leave.
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
But Byford wants to get moving now—order new cars, replace old track, resignal multiple lines.
From The New Yorker ● Jul. 2, 2018