The Collaborative International Dictionary of English v.0.48:

feal \fe"al\ (f[=e]"al), a. [OF. feal, feel, feeil, fedeil, F.
   fid[`e]le, L. fidelis faithful, fr. fides faith. See
   Faith.]
   Faithful; loyal. [Obs.] --Wright.
   [1913 Webster]

V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

FEAL
       Fast Data Encipherment Algorithm (DES, cryptography)


Bouvier's Law Dictionary, Revised 6th Ed (1856):

FEAL. Faithful. This word is not used.