'aweary' originates from Middle English, specifically the form 'a-weary', where the prefix 'a-' came from Old English prepositional/adverbial uses meaning 'on, in' and 'weary' derives from Old English 'werig' meaning 'tired'.

'aweary' changed from Middle English 'a-weary' (literally 'on/in weary') and ultimately traces back to Old English 'werig'; the prefix 'a-' was a productive element in forming adjectives and adverbs in Middle English.

Initially it meant 'in a state of weariness' and over time retained that basic meaning; its use has become mainly archaic or literary in modern English.