a. [f. L. lībrāt-, ppl. stem of lībrā-re to LIBRATE.] Having a motion like that of the beam of a balance; oscillatory.
1668. Phil. Trans., III. 809. That there is a Libratory motion in Comets as well as in the Moon.
1801. Trans. Soc. Arts, XIX. 257. The beam … acquired a libratory motion.
1804. C. B. Brown, trans. Volney’s View Soil U.S., 203. Just as the sea experiences a libratory motion, while its interior currents remain undisturbed.
1874. Edin. Rev., No. 285. 87. The libratory swaying to and fro of the moon.
