Source : Webster's Revised Unabridged Dictionary (1913)

Non- \Non-\ [L. non, OL. noenu, noenum, fr. neoenum, lit., not
   one. See {None}.]
   A prefix used in the sense of not; un-; in-; as in
   nonattention, or non-attention, nonconformity, nonmetallic,
   nonsuit.

   Note: The prefix non- may be joined to the leading word by
         means of a hyphen, or, in most cases, the hyphen may be
         dispensed with. The list of words having the prefix
         non- could easily be lengthened.