'weary' originates from Old English, specifically the word 'werig', where 'werig' meant 'tired' or 'exhausted'.

'weary' changed from the Old English word 'werig' into Middle English forms such as 'weri'/'wery' and eventually became the modern English word 'weary'.

Initially, it meant 'tired' or 'exhausted', and over time it has kept that core sense while also extending to meanings like 'bored' or 'satiated' (in the sense of being tired of something).