an object (especially a ring) formerly used to impress a picture into the sealing wax of a document as a proof of its origin

The act of signifying, or something that is signified; significance. / Evidence for the existence of something. / A meaning of a word.

A traffic light.

Somebody employed to operate the signals and points of a railway. / A member of the armed forces responsible for signalling.

(computer science) The byte of a multibyte number with the greatest importance: that is, the byte stored first on a big-endian system or last on a little-endian system.

(telephony) An audible signal on a voice phone line that sounds more frequently than a standard busy signal, indicating that no transmission path to the called phone number is available.

One who signs something. / One who uses sign language.

(US, Australia) Any of the large metal boxes containing traffic signal controls, found at roadsides and intersections, and often made available by the local council for artistic work.

(US) A board carrying a sign, or on which signs may be posted.

plural of traffic signal box