rails
n. countable A2 Elementary US //ˈɹeɪɫz// UK //ɹˈeɪlz// rails
n. the long metal bars that trains travel on. They are usually made of steel and come in pairs to form a track.
n. the parallel steel bars that form a track for locomotives and other wheeled vehicles. Often used in the plural to refer to the entire railway system.
The train stayed on the rails during the sharp turn.
Workers spent the weekend replacing the rusted rails on the main line to ensure passenger safety.
The expansion of the national network required thousands of tons of high-grade steel to manufacture the rails necessary for high-speed transit.
Usage
Commonly used in the plural ('rails') when referring to the track; also appears in the idiom 'go off the rails' to describe something failing or becoming chaotic.