'erratic' originates from Latin, specifically the word 'erraticus,' where 'err-' meant 'to wander.' 'Apply' comes from Latin 'applicare,' meaning 'to attach or join.'

'erraticus' transformed into the Old French word 'erratique,' and eventually became the modern English word 'erratic.' 'Applicare' evolved into the Old French 'appliquer,' leading to the modern English 'apply.'

Initially, 'erratic' meant 'wandering' and 'apply' meant 'to attach,' but over time, 'erratically-applied' evolved to mean 'inconsistently used.'