'unfamiliarity' originates from the prefix 'un-' meaning 'not' and the word 'familiar,' which comes from Latin 'familiaris,' meaning 'of a household, domestic.'

'familiaris' transformed into the Old French word 'familier,' and eventually became the modern English word 'familiar,' with 'unfamiliarity' forming by adding the prefix 'un-' and the suffix '-ity.'

Initially, 'familiaris' meant 'of a household,' but over time it evolved into its current meaning of 'well-known or recognized.'