'dioeciousness' originates from New Latin 'dioecius', specifically ultimately from the Greek word 'dioikos', where 'di-' meant 'two' and 'oikos' meant 'house'.

'dioeciousness' changed from the Greek element 'dioikos' through New Latin 'dioecius' into the English adjective 'dioecious', and the noun 'dioeciousness' was later formed by adding the suffix '-ness' to that adjective.

Initially it literally meant 'two‑housed' (two households); over time it evolved into the biological sense of 'having male and female reproductive structures on separate individuals'.