'dawny' originates from English, specifically the word 'dawn' with the adjectival suffix '-y', where 'dawn' meant 'the beginning of the day' and '-y' meant 'characterized by' (forming adjectives).

'dawn' comes from Old English 'dagian' (to become day) and the noun 'dag'/'dæg' (day), ultimately from Proto-Germanic '*dagaz'; through Middle English forms such as 'daw(n)' it became modern English 'dawn', and the adjective 'dawny' was formed by adding the suffix '-y'.

Initially 'dawn' referred to 'the beginning of day' or the action 'to become day'; 'dawny' has retained the sense 'pertaining to dawn' but is now largely literary or archaic in use.