sleeper Copy link Outline I. One who sleepsII. A beam on which joists rest. *trabs in solo collocata quae tigna transversaria (joists) sustinet. • sleeper: I. One who sleeps: dormītor, Mart. 10, 4, 4: better expr. by vb. or phr to be a poor s., brevissimi esse somni, Suet. Claud. 33. Dormitator in Pl. Trin. 4, 2, 20 is a thief who sleeps by day only. II. A beam on which joists rest. *trabs in solo collocata quae tigna transversaria (joists) sustinet.