'pain-aware' originates from modern English as a compound of 'pain' and 'aware'. 'pain' originates from Latin, specifically the word 'poena', where 'poena' meant 'penalty' or 'suffering'; 'aware' originates from Old English, specifically the word 'gewær', where 'gewær' meant 'cautious' or 'watchful'.

'pain' passed into English via Old French 'peine' (from Latin 'poena') and entered Middle English as 'peine'/'pain'; 'aware' evolved from Old English 'gewær' through Middle English forms (e.g. 'awær') to modern 'aware'. The compound 'pain-aware' is a recent formation in modern English combining the two existing words.

Initially, 'poena' in Latin meant 'penalty', and 'pain' shifted in English to mean 'suffering'; 'aware' initially meant 'cautious' or 'watchful'. Over time, combining them produced the modern descriptive compound meaning 'conscious of pain'.