Lewis & Short

rĕlĕvātĭo, ōnis, f. [relevo].

  1. I. = ἐναιώρημα (Hippoc.), scum: ut urina nullam faciat relevationem, Cael. Aur. Tard. 5, 3, 55.
  2. II. A lightening, alleviation, relief (postclass. and very rare): oneris, Front. Ep. ad M. Caes. 4, 13.
    Absol. (opp. gravatio), Cael. Aur. Tard. 5, 10, 96; Octav. Hor. 1, 9.