[sem-uh-fawr, -fohr] 
noun, verb, -phored, -phor⋅ing.| 1. | an apparatus for conveying information by means of visual signals, as a light whose position may be changed. |
| 2. | any of various devices for signaling by changing the position of a light, flag, etc. |
| 3. | a system of signaling, esp. a system by which a special flag is held in each hand and various positions of the arms indicate specific letters, numbers, etc. |
| 4. | to signal by semaphore or by some system of flags. |
[sem-uh-fawr-ik, -for-] , sem⋅a⋅phor⋅i⋅cal, adjective 
əˌfɔr