The Collaborative International Dictionary of English v.0.48:

Kneel \Kneel\ (n[=e]l), v. i. [imp. & p. p. Knelt (n[e^]lt) or
   Kneeled (n[=e]ld); p. pr. & vb. n. Kneeling.] [OE.
   knelen, cneolien; akin to D. knielen, Dan. kn[ae]le. See
   Knee.]
   To bend the knee; to fall or rest on the knees; -- sometimes
   with down.
   [1913 Webster]

   Note: The act of kneeling, when performed in front of a
         person, is often done as a sign of respect, humility,
         or supplication. It has a similar significance when
         performed in front of religious objects, such as an
         altar or shrine.
         [PJC]

               And he kneeled down, and cried with a loud voice,
               Lord, lay not this sin to their charge. --Acts
                                                  vii. 60.
         [1913 Webster]

               As soon as you are dressed, kneel and say the
               Lord's Prayer.                     --Jer. Taylor.
         [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Knelt \Knelt\,
   imp. & p. p. of Kneel.
   [1913 Webster]