Feminine participle present passive of oikeo (as noun, by implication, of ge); land, i.e. The (terrene part of the) globe; specially, the Roman empire -- earth, world.
KJV: And there stood up one of them named Agabus, and signified by the spirit that there should be great dearth throughout all the world: which came to pass in the days of Claudius Caesar.
NASB: One of them named Agabus stood up and began to indicate by the Spirit that there would certainly be a great famine all over the world. And this took place in the reign of Claudius.