An event or emanation to which a sensing device gives an undesired positive response.

plural of signal box

A building, typically adjacent to or spanning a railway line, from where signals, points and (sometimes) level crossings are controlled. / The alarm-box of a police or fire-alarm system.

(biochemistry) A series of chemical reactions within a cell which start when a transmembrane protein comes into contact with a chemical signal, resulting in a second messenger being triggered.

(rail transport) Synonym of signal box

plural of signal cabin

Any signal sent by semaphore.

(rail transport, US) A structure built over railroad tracks on which signals are mounted. / (nautical) An open platform by the navigating bridge of a warship for the use of signalmen.

plural of signal bridge

simple past tense and past participle of signal boost