'erratic' originates from Latin, specifically the word 'erraticus,' where 'err-' meant 'to wander.' 'Change' originates from Old French 'changier,' which meant 'to alter or exchange.'

'erraticus' transformed into the Old French word 'erratique,' and eventually became the modern English word 'erratic.' 'Changier' evolved into the Middle English 'chaungen,' leading to the modern English 'change.'

Initially, 'erratic' meant 'wandering' and 'change' meant 'to alter,' but over time, 'erratically-changed' evolved to mean 'changed in an unpredictable manner.'