'venereal-prophylactic' is a compound of two elements: 'venereal' and 'prophylactic'. 'venereal' originates from Latin, specifically the word 'venereus'/'venerealis' (from 'Venus'), where 'Venus' referred to the Roman goddess associated with love/sexual desire; 'prophylactic' originates from Greek, specifically the word 'prophylaktikos', where 'pro-' meant 'before' and 'phylassein' meant 'to guard or protect'.

'venereal' came into English via Latin 'venerealis' and Middle English forms, keeping its link to sexual matters; 'prophylactic' passed from Greek 'prophylaktikos' into Late Latin and French ('prophylactique') before entering English as 'prophylactic'. The compound form is a modern English formation combining the two terms.

Initially, the element 'venereal' denoted things relating to Venus or sexual love and 'prophylactic' meant 'guarding beforehand'; over time, the compound has come to specifically mean 'intended to prevent sexually transmitted (venereal) disease'.