'backcross' originates from English, specifically a compound of the words 'back' and 'cross', where 'back' meant 'back; again' and 'cross' meant 'to mate (a crossing of organisms)'.

'backcross' developed in scientific/genetics usage in the late 19th to early 20th century from the phrase 'back cross' (two-word form) and eventually became the single word 'backcross' in modern usage.

Initially it referred specifically to 'a cross made back to one parent'; over time the term has remained focused on that genetic procedure and its derivatives (as verb and noun) without major change in core meaning.