'boredly' originates from English, specifically formed by adding the adverbial suffix '-ly' to the adjective 'bored', where the suffix '-ly' (from Old English '-lic' via Middle English '-lich') meant 'in the manner of'.

'bored' developed as the past participle/adjective from the verb 'bore' (Middle English forms such as 'boren'/'boren' or adjectival 'borede'), and later the adverbial form 'boredly' was created by attaching '-ly' to that adjective.

Initially, the root verb 'bore' meant 'to make weary or dull', and 'bored' meant 'made weary'; over time the adverbial form 'boredly' came to mean 'in a manner showing boredom' without changing that basic idea.