Source : Webster's Revised Unabridged Dictionary (1913)

Suffix \Suf"fix\, n. [L. suffixus, p. p. of suffigere to fasten
   on, to affix; sub under + figere to fix: cf. F. suffixe. See
   {Fix}.]
   1. A letter, letters, syllable, or syllables added or
      appended to the end of a word or a root to modify the
      meaning; a postfix.

   2. (Math.) A subscript mark, number, or letter. See
      {Subscript}, a.

Suffix \Suf*fix"\, v. t. [imp. & p. p. {Suffixed}; p. pr. & vb.
   n. {Suffixing}.]
   To add or annex to the end, as a letter or syllable to a
   word; to append.

Source : WordNet®

suffix
     v : attach a suffix to; "suffix words" [ant: {prefix}]

suffix
     n : an affix that is added at the end of the word [syn: {postfix}]