The Collaborative International Dictionary of English v.0.48:

Oscillatory \Os"cil*la*to*ry\, a. [Cf. F. oscillatoire. See
   Oscillate.]
   Moving, or characterized by motion, backward and forward like
   a pendulum; swinging; oscillating; vibratory; as, oscillatory
   motion.
   [1913 Webster]

WordNet (r) 3.0 (2006):

oscillatory
    adj 1: having periodic vibrations [syn: oscillatory,
           oscillating]

Moby Thesaurus II by Grady Ward, 1.0:

46 Moby Thesaurus words for "oscillatory":
   alternate, beating, circling, cyclic, epochal, even, every other,
   fluctuant, fluctuating, fluctuational, harmonic, intermittent,
   isochronal, libratory, measured, metronomic, nutational,
   oscillating, pendular, pendulating, pendulous, periodic,
   periodical, pulsing, reciprocal, recurrent, recurring, resonant,
   rhythmic, rotary, seasonal, serial, shilly-shally,
   shilly-shallying, steady, undulant, undulatory, vacillating,
   vacillatory, vibratile, vibrating, vibratory, wavelike, wavering,
   wheeling, wobbly