Lewis Short
rĕlĕvātĭo (noun F) : id..
* = ἐναιώρημα (Hippoc.), scum: ut urina nullam faciat relevationem,Cael. Aur. Tard. 5, 3, 55.
* 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.
Charlton T. Lewis, Charles Short, A Latin Dictionary