Source : Webster's Revised Unabridged Dictionary (1913)

Gruntle \Grun"tle\, v. i. [Freq. of grunt.]
   To grunt; to grunt repeatedly. [Obs.]

Source : WordNet®

gruntle
     v : cause to be more favorably inclined; gain the good will of;
         "She managed to mollify the angry customer" [syn: {pacify},
          {lenify}, {conciliate}, {assuage}, {appease}, {mollify},
          {placate}, {gentle}]