'libido-affirming' is a modern compound formed from the noun 'libido' and the present-participial adjective 'affirming'. 'libido' originates from Latin, specifically the word 'libido', where it meant 'desire' or 'lust'; 'affirming' (from the verb 'affirm') traces to Latin 'affirmare' (via Old French 'affirmer'), where 'firmare' meant 'to make firm' or 'to confirm'.

'libido' entered English via Latin usage and was popularized in psychoanalytic theory (notably Freud) in the late 19th and early 20th centuries; 'affirm' came into English via Old French 'affirmer' and Middle English forms before becoming modern 'affirm'/'affirming'. The compound 'libido-affirming' is a recent English formation combining these elements to describe something that affirms or strengthens desire.

Initially, 'libido' meant 'desire' and 'affirm' meant 'to make firm/confirm' as separate senses; over time the compound evolved to mean 'that which reinforces or affirms sexual desire', a specialized descriptive adjective in modern usage.