'ecumenical' originates from Greek, specifically the word 'oikoumenikos,' where 'oikos' meant 'house' and 'oikoumenē' meant 'the inhabited world.'

'oikoumenikos' transformed into the Latin word 'oecumenicus,' and eventually became the modern English word 'ecumenical' through Middle English.

Initially, it meant 'pertaining to the whole world,' but over time it evolved into its current meaning of 'promoting unity among Christian churches.'