'immortality-affirming' is a modern English compound formed from the noun 'immortality' and the present-participial adjective 'affirming'. 'Immortality' ultimately comes from Latin elements meaning 'not' + 'mortal', and 'affirming' comes from Latin 'affirmare' meaning 'to make firm' or 'to assert'.

'immortality' entered English via Late Latin 'immortalitas' (from 'in-' + 'mortalis') and Middle English usage; 'affirming' derives from Latin 'affirmare' through Old French/Latin verbal forms and Middle English participial uses. The compound itself is a productive modern English formation combining the noun and participle into a descriptive adjective.

Individually, 'immortality' originally meant 'the state of not being mortal' and 'affirm' meant 'to assert or confirm'; together as 'immortality-affirming' the compound specifically conveys the act or quality of asserting/confirming immortality in a text, belief, or portrayal.