'self-fertilization' originates from English, specifically the words 'self' and 'fertilization', where 'self' comes from Old English 'self' meaning 'the same person/thing' and 'fertilization' derives from Latin 'fertilis' meaning 'fruitful'.

'fertilization' developed from Latin 'fertilis' → Late Latin/Medieval Latin forms related to 'fertilis', passed into Old French as forms like 'fertiliser' and later into Middle English/French-influenced English as 'fertilize' and then 'fertilization'; 'self' is a native Old English word that remained largely unchanged, and the compound 'self-fertilization' formed in Modern English to describe the biological process.

Initially, the root idea was 'to make fruitful' (general sense of making productive), and over time it specialized into the biological sense of gamete fusion resulting in fertilization, hence the modern meaning 'fertilization carried out by the same individual.'