The Collaborative International Dictionary of English v.0.48:

Reflux \Re"flux`\ (r?"fl?ks`), a.
   Returning, or flowing back; reflex; as, reflux action.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Reflux \Re"flux`\, n. [F. reflux. See Refluent, Flux.]
   A flowing back, as the return of a fluid; ebb; reaction; as,
   the flux and reflux of the tides.
   [1913 Webster]

         All from me
         Shall with a fierce reflux on me redound. --Milton.
   [1913 Webster]

WordNet (r) 3.0 (2006):

reflux
    n 1: an abnormal backward flow of body fluids
    2: the outward flow of the tide [syn: ebb, reflux]

Moby Thesaurus II by Grady Ward, 1.0:

140 Moby Thesaurus words for "reflux":
   Brownian movement, Charybdis, Maelstrom, action and reaction,
   advance, angular motion, answer, ascending, ascent,
   automatic reaction, autonomic reaction, axial motion, back stream,
   backflow, backflowing, backing, backset, backsliding,
   backward motion, backward step, backwash, backwater, bounceback,
   career, climbing, countercurrent, counterflow, counterflux, course,
   current, descending, descent, direct tide, downward motion, drift,
   driftage, ebb, ebb and flow, ebb tide, ebbing, echo, eddy, flight,
   flood, flood tide, flow, flux, flux and reflux, forward motion,
   full tide, gulf, gurge, high tide, high water, lapse, low tide,
   low water, lunar tide, maelstrom, mounting, neap, neap tide,
   oblique motion, ongoing, onrush, opposite tide, passage, plunging,
   predictable response, progress, radial motion, random motion,
   reaction, recession, recidivation, recidivism, reentry, reflection,
   reflex, reflex action, reflowing, refluence, regress, regression,
   regurgitation, relapse, reply, respondence, response, retroaction,
   retrocession, retroflexion, retrogradation, retrogression,
   retrusion, return, reverberation, revulsion, rip, riptide, rise,
   rising, rollback, run, rush, set, setback, sideward motion,
   sinking, soaring, solar tide, spring tide, sternway, stream,
   subsiding, swirl, thalassometer, throwback, tidal amplitude,
   tidal current, tidal current chart, tidal flow, tidal range, tide,
   tide chart, tide gate, tide gauge, tide race, tide rip, tidewater,
   tideway, traject, trajet, trend, twirl, unthinking response,
   upward motion, vortex, whirl, whirlpool