an alarm that alerts security personnel or the police without the knowledge of the intruder or criminal whose presence triggers it:
The silent alarm set off a flashing light at the police station.
any visual rather than audible alarm.
- Silent area
silent area n. An area of the cerebral or cerebellar surface on which lesions cause no sensory or motor symptoms.
or silent trade noun 1. dumb barter.
- Silent but deadly
noun an instance of stinky but silent flatulence; Abbr. SBD Examples Someone done let loose a silent but deadly. Usage Note slang; also adj. sidewinder 2
noun 1. a small receptacle having a handle and a hinged lid, used for collecting the contents of ashtrays, crumbs from a dinner table, etc., for disposal.