Webster’s Revised Unabridged Dictionary · 1913
Non-
Non- (nŏn·). [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.
☞ 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.