STOPLIGHT
stoplight, brake light
(noun) a red light on the rear of a motor vehicle that signals when the brakes are applied to slow or stop
Source: WordNet® 3.1
Etymology
Noun
stoplight (plural stoplights)
(US) A traffic control signal, traditionally consisting of three lights, colored green, yellow/amber, and red, meaning proceed, prepare to stop, and stop, respectively.
A light on the rear of a vehicle that is activated when braking; a brake light.
Usage notes
The two-word form stop light was initially more common, but its usage plateaued around 1950, whereas usage of stoplight increased continually since that year, overtaking stop light around 1970.
Synonyms
• traffic light
• traffic signal (US)
• robot (South African)
Anagrams
• lightpost, spotlight, toplights
Source: Wiktionary