'babysit' originates from English, specifically the compound of 'baby' + 'sit', where 'baby' meant 'infant' and 'sit' meant 'to remain in place/attend to (originally to seat or stay).'

'baby' comes from Middle English forms such as 'babe' and ultimately imitative formations; 'sit' comes from Old English 'sittan'. The compound 'babysit' was formed in modern English (20th century) to mean 'sit with a baby/child'.

Initially it meant 'to sit with or remain near a baby (literally)'; over time it came to mean more generally 'to care for a child temporarily,' often used for short-term, informal childcare.