Lewis & Short

ăd-usque, for usque ad (like abusque for usque ab); hence,

  1. I. Prep. with acc., to, quite or even to, all the way to, as far as (rare, not used in Cic., and for the most part only in the poets of the Aug. per. (metri gratiā) and their imitators among later prose writers): adusque columnas, Verg. A. 11, 262: adusque Bari moenia piscosi, Hor. S. 1, 5, 96; 97; Gell. 15, 2.
  2. II. Adv., a strengthened form for usque, throughout, wholly, entirely: oriens tibi victus adusque qua, etc., Ov. M. 4, 20: adusque deraso capite, App. M. 2, p. 147 (cf. Plaut. Bacch. 5, 2, 7: attonsae hae quidem umbrae usque sunt), v. Hand, Turs. I. p. 189.