Source : Webster's Revised Unabridged Dictionary (1913)

Underfong \Un`der*fong"\, v. t. [AS. underfongen, p. p. of
   underf?n to undertake; under under + f?n to take. See {Fang}
   to seize.]
   1. To undertake; to take in hand; to receive. [Obs.] --Piers
      Plowman. Rom. of R.

   2. To insnare; to circumvent. [Obs.] --Spenser.

   3. To sustain; to support; to guard. --Nash.