The Collaborative International Dictionary of English v.0.48:

genuflection \gen`u*flec"tion\, genuflexion \gen`u*flex"ion\, n.
   [F. g['e]nuflexion, fr. LL. genuflexio, fr. L. genu knee +
   flexio a bending, fr. flectere, flexum, to bend. See Knee,
   Flexible.]
   The act of bending the knee, particularly in worship or
   reverence. --Bp. Stillingfleet.
   [1913 Webster]

WordNet (r) 3.0 (2006):

genuflection
    n 1: the act of bending the knees in worship or reverence [syn:
         genuflection, genuflexion]

Moby Thesaurus II by Grady Ward, 1.0:

31 Moby Thesaurus words for "genuflection":
   bend, bending the knee, bob, bow, bowing and scraping, crouch,
   curtsy, dipping the colors, duck, homage, inclination, kneeling,
   kowtow, making a leg, nod, obeisance, obsequiousness,
   presenting arms, prostration, reverence, salaam, salutation,
   salute, scrape, servility, squat, standing at attention, stoop,
   submission, submissiveness, supination