What does taillight mean?
A taillight is a lamp mounted at the back of a vehicle or bicycle. Its basic purpose is to make the vehicle visible to people approaching from behind, especially in darkness or bad weather. On many vehicles, a taillight also becomes brighter when the brakes are applied, helping drivers behind recognize that the vehicle is slowing or stopping. The word is common in automotive, cycling, traffic-safety, and repair contexts. People may refer to a damaged taillight as broken, cracked, or faulty, and discussions often concern replacing a bulb, lens, or complete assembly. Although “tail lamp” and “rear light” can be used similarly, taillight is especially associated with the familiar red light at the back of a car. The term should not be confused with a headlight, which is at the front, or a brake light, which can describe the specific braking function of a rear lamp.
nounA light on the rear of a vehicle or bicycle that makes it visible from behind and often becomes brighter when the vehicle brakes. The term can also refer more broadly to a lamp at the back of a vehicle.
- A light at the rear of a vehicle, used to make the vehicle visible from behind and to indicate braking or a change in direction, depending on the vehicle and local regulations.
"The car's broken taillight made it difficult for drivers behind to see when she braked."
"Cyclists should check that both taillights are working before riding after dark."
"The police officer asked the driver to repair the broken taillight before continuing."
The plural is formed by adding -s and is commonly used for multiple rear lights or for the lights collectively.
"The technician replaced both taillights after the car was rear-ended."
A taillight may look like one lamp, but on many vehicles it has several jobs: marking the car's width, showing its position, and brightening to signal braking.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of taillight
The word is a compound of “tail” and “light.” “Tail” comes from Old English tæl, referring to the rear or hind part of an animal, while “light” comes from Old English lēoht, meaning illumination or a source of light. The compound appears in the language during the period when motor vehicles were becoming established, reflecting the growing need to describe the lights fitted to the front and rear of vehicles.
How taillight is actually used
In general use, taillight refers to the rear lamp of a vehicle, especially a car. The term is also used for the rear lamp of a bicycle or motorcycle. In some contexts, it specifically means the red rear light that brightens when braking, but usage varies.
Easily confused with taillight
A taillight is mounted at the rear of a vehicle, while a headlight is mounted at the front and illuminates the road ahead.
A taillight is the rear lamp generally, whereas a brake light is the part of the rear lighting system that brightens when the driver brakes.