Source : Webster's Revised Unabridged Dictionary (1913)

Flagellate \Flag"el*late\, v. t. [imp. & p. p. {Flagellated}; p.
   pr. & vb. n. {Flagellating}.] [L. flagellatus, p. p. of
   flagellare to scoure, fr. flagellum whip, dim. of flagrum
   whip, scoure; cf. fligere to strike. Cf. {Flall}.]
   To whip; to scourge; to flog.

Flagellate \Fla*gel"late\, a.
   1. Flagelliform.

   2. (Zo["o]l.) Of or pertaining to the Flagellata.

Source : WordNet®

flagellate
     adj : having or resembling a flagellum or flagella [syn: {flagellated},
            {whiplike}]

flagellate
     n : usually nonphotosynthetic free-living protozoan with
         whiplike appendages; some pathogens of humans and other
         animals [syn: {flagellate protozoan}, {flagellated
         protozoan}, {mastigophoran}, {mastigophore}]

flagellate
     v : whip; "The religious fanatics flagellated themselves" [syn:
         {scourge}]