Definition of third rail
1 : a metal rail through which electric current is led to the motors of an electric vehicle (such as a subway car)
2 : a controversial issue usually avoided by politicians
Examples of third rail in a sentence
Social Security is the third rail of American politics.
First Known Use of third rail
THIRD RAIL Defined for English Language Learners
Definition of third rail for English Language Learners
: a metal rail on a train track that carries electric current to the train's motor
: a difficult issue that politicians try to avoid talking about
Seen and Heard
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