un-1
Pronunciation: /ʌn/
prefix

Origin:
Old English, of Germanic origin; from an Indo-European root shared by Latin in- and Greek a-

The prefixes un- and non- both mean ‘not’, but there is often a distinction in terms of emphasis. un- tends to be stronger and less neutral than non-: consider the differences between unacademic and non-academic, for example ( his language was refreshingly unacademic; a non-academic life suits him).