Source : Webster's Revised Unabridged Dictionary (1913)

Water chinquapin \Wa"ter chin"qua*pin\ (Bot.)
   The American lotus, and its edible seeds, which somewhat
   resemble chinquapins. Cf. {Yoncopin}.

Source : WordNet®

water chinquapin
     n 1: water lily of eastern North America having pale yellow
          blossoms and edible globular nutlike seeds [syn: {American
          lotus}, {yanquapin}, {Nelumbo lutea}]
     2: edible nutlike seeds of an American lotus having the flavor
        of a chinquapin