'collectedly' originates from Modern English as the adverbial form of the adjective 'collected', itself formed by adding the adverbial suffix '-ly' to 'collected'.

'collected' comes from Middle English 'collect(e)d', from Old French/Latin influence, which in turn derives from Latin 'collectus', the past participle of 'colligere' (to gather). The Modern English adverb 'collectedly' developed by attaching the English adverbial suffix '-ly' (from Old English '-lic') to the adjective.

Initially related to the sense of 'gathered together' (from Latin 'colligere' = 'to gather'), the word evolved to mean 'mentally gathered' or 'composed', and 'collectedly' now means 'in a composed or calm manner'.