taillight means one of a pair of red lights mounted on the rear of a vehicle, so it can be seen from the rear at night. Lexicurio rates it Distinctive — a strength score of 66 out of 100.
Etymology
From tail + light.
noun
- One of a pair of red lights mounted on the rear of a vehicle, so it can be seen from the rear at night.“All moved to the front street, where Grierson snibbed on his tail-light and turned to ask the trooper, "They've got the main road ploughed up farther on, haven't they?"”