(*) 1. As applied to electronics, any transmitted electrical impulse. 2. Operationally, a type of message, the text of which consists of one or more letters, words, characters, signal flags, visual displays, or special sounds with prearranged meaning, and which is conveyed or transmitted by visual, acoustical, or electrical means.
SIGNAL
Meaning of SIGNAL in English
DOD English dictionary of military terms. Английский словарь военных терминов DOD. 2012