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):

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