Lewis & Short

stlāta, ae, f. [1. latus, q. v. init.], a kind of ship: stlata genus navigii latum magis quam altum, et a latitudine sic appellatum, sed consuetudine, quā stlocum pro locum et stlitem pro litem dicebant, Fest. p. 312 Müll.; cf. Aus. Ep. 22, 31; Gell. 10, 25, 5.
Acc. to Caper, Orth. p. 2246 P., and Gloss. Philox. s. h. v., a kind of piratical vessel or corsair: stlatta, πειρατικοῦ σκάφεος εἶδος.