semaphore

noun

1. any apparatus for signaling, as the arrangement of lights, flags, and mechanical arms on railroads
2. a system of signaling by the use of two flags, one held in each hand: the letters of the alphabet are represented by the various positions of the arms
3. any system of signaling by semaphore

Origin: Fr sémaphore < Gr sēma, sign (see semantic) + -phoros: see -phore

transitive verb, intransitive verb semaphored, semaphoring