The Collaborative International Dictionary of English v.0.48:
Cross-tie \Cross"-tie`\ (-t?`), n. (Railroad) A sleeper supporting and connecting the rails, and holding them in place. [1913 Webster]WordNet (r) 3.0 (2006):
crosstie n 1: one of the cross braces that support the rails on a railway track; "the British call a railroad tie a sleeper" [syn: tie, railroad tie, crosstie, sleeper]