The word 'improve' began life as a term of property law, not personal betterment. Anglo-Norman landlords used emprower to describe the act of enclosing common land and turning it to private profit, from Old French prou (profit). When the word entered Middle English as improwen in the 15th century, it retained this narrow agricultural sense. The spelling shifted dramatically in the 17th century, with the -owe ending replaced by -ove, possibly through confusion with 'prove' or 'approve,' though neither word is etymologically related. The semantic broadening happened in parallel: by the 1640s, writers were using 'improve' to mean general betterment of anything, not just land. The original property sense survives in real estate law, where 'improvements' specifically means structural additions that increase a property's market value — a direct echo of the medieval meaning.