Non- (n&obreve_;n-) pref. [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.
[1913 Webster]

&hand_; 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.
[1913 Webster]