lībrātĭo — Lewis & Short
lībrātĭo, ōnis, f.libro.
I A making level, levelling:
fortasse qui Archimedis libros legit, dicet non posse fieri veram ex aqua librationem,Vitr. 8, 6, 3.—
II A horizontal position, level:
circa terrae librationem,Vitr. 6, 1, 5.—
III A hurling off, hurling, slinging, Diom. p. 473 P.