Lewis & Short

tractōrĭus, a, um, adj. [traho].

  1. I. Of or for drawing or hoisting: genus machinarum, Vitr. 10, 1.
  2. II. Substt.: tractō-rĭa, ae, f. (sc. epistula), a letter of invitation or summons, Aug. Ep. 217.
    1. B. trac-tōrĭae, ārum, f. (sc. litterae), an imperial letter containing an order to provide a person with necessaries on his journey: de tractoriis et stativis, Cod. Just. 15, 52.