Lewis & Short

lăvātĭo, ōnis, f. [lavo], a washing, bathing, bath.

  1. I. In abstr.: quid ea messis attinet ad meam lavationem? Plaut. Most. 1, 3, 4; Cic. ap. Col. 12, 3, 2: lavatio calida et pueris et senibus apta est, Cels. 1, 3, § 71; 79; cf.: boves lavatione calidae aquae traduntur pinguescere, Plin. 8, 45, 70, § 178.
  2. II. Transf.
    1. A. Bathing apparatus: ut lavatio parata sit, Cic. Fam. 9, 5, 3: argentea, Phaedr. 4, 5, 22; Dig. 34, 2, 25, § 10.
    2. B. A bathing-place, bathing-room, bath: in versura porticus frigida lavatio, quam Graeci λουτρὸν vocitant, Vitr. 5, 11; Dig. 19, 2, 30, § 1; Inscr. Grut. 444, 8; 473, 1 al.