'nonfan' originates from English, specifically the prefix 'non-' and the word 'fan', where 'non-' meant 'not' and 'fan' is short for 'fanatic' (from Latin 'fanaticus') originally meaning 'enthusiast/zealot'.

'fan' developed as a short form of 'fanatic' (Latin 'fanaticus'); the English prefix 'non-' was attached in modern usage to produce 'non-fan' (written also as 'nonfan'), which then yields the plural 'nonfans'.

Initially, 'fan' derived from 'fanatic' with a sense of excessive zeal; over time 'fan' softened to mean simply an 'enthusiast', and 'nonfan' came to mean 'someone who is not an enthusiast' (neutral or uninterested, sometimes opposed).