1. system of signaling: a system for sending messages using hand-held flags that are moved to represent alphabetical letters
2. mechanical signaling device: a signaling device for sending information over distances using mechanically operated arms or flags mounted on a post, especially on a railroad
transitive and intransitive verb (past and past participlesem·a·phored, present participlesem·a·phor·ing, 3rd person present singularsem·a·phores)
Definition:
use semaphore to signal: to send messages using semaphore
[Early 19th century. Via French sémaphore "sign-bearer" < Greek sēma "sign, mark"]