Lewis & Short

oscillo, āre, v. n. [2. oscillum], to swing, swing one’s self: oscillum Santra dici ait, quod oscillent, id est inclinent, praecipitesque in os ferantur, Fest. p. 194, 9 and 10 Müll.
Pass.: osculor, Mythogr. Lat. 1, 19 fin.
Hence, oscillans, antis, P. a.; as subst., a swinger: oscillantes, ait Cornificius, ab eo, quod os celare soliti personis propter verecundiam, qui eo genere lusūs utebantur, Fest. p. 194 Müll.