[1605–15; un-1 + repair1 + -able]This word is first recorded in the period 1605–15. Other words that entered Englishat around the same time include: displacement, ferrule, inverse, pivot, seriesun- is a prefix meaning “not,” freely used as an English formative, giving negative oropposite force in adjectives and their derivative adverbs and nouns (unfair; unfairly; unfairness; unfelt; unseen; unfitting; unformed; unheard-of; un-get-at-able), and less freely used in certain other nouns (unrest; unemployment); -able is a suffix meaning “capable of, susceptible of, fit for, tending to, given to,”associated in meaning with the word able, occurring in loanwords from Latin (laudable); used in English as a highly productive suffix to form adjectives by addition tostems of any origin (teachable; photographable)