sleeper (sleepers plural )
1 n-count You can use sleeper to indicate how well someone sleeps. For example, if someone is a light sleeper, they are easily woken up.
I'm a very light sleeper and I can hardly get any sleep at all...
2 n-count In British English, a sleeper is a carriage on a train containing beds for passengers to sleep in at night, or a section of such a carriage. The usual American words are sleeping car for the carriage and roomette for the section.
3 n-count A sleeper is a train with beds for its passengers to sleep in at night.
(BRIT)
4 n-count Railway sleepers are large heavy beams that support the rails of a railway track.
(BRIT)
in AM, use ties