(properly: the land that is being inhabited, the land in a state of habitation), the inhabited world, that is, the Roman world, for all outside it was regarded as of no account.
Strong's:
οἰκουμένη
land, i.e. the (terrene part of the) globe; specially, the Roman empire Derivation: feminine participle present passive of G3611 (as noun, by implication, of G1093);
οἰκουμένη, -ης, ἡ (fern. Pres. pass. ptcp. of οἰκέω; sc. γῆ) [in LXX chiefly for תֵּבֵל, אֶרֶץ ;] the inhabited earth; __(a) in cl., the countries occupied by Greeks, as disting. from barbarian lands (Hdt., Dem., al.); __(b) in later writers, the Roman world: Refs Luk.2:1, Act.11:28 24:5; by meton., of its inhabitants : Refs Act.17:6 19:27; __(with) in LXX (Refs Psa.23:1 71:8, al.) and NT, also of the whole inhabited world: Refs Mat.24:14, Luk.4:5 21:26, Rom.10:18, Heb.1:6, Rev.3:10 16:14; by meton. (ut supr.), Refs Act.17:31, Rev.12:9; __(d) of the Messianic age, ἡ οἰ. ἡ μέλλουσα = ὁ αἰὼ ὁ μέλλων: Heb.2:5.† (AS)
Thayer:
1) the inhabited earth 1a) the portion of the earth inhabited by the Greeks, in distinction from the lands of the barbarians 1b) the Roman empire, all the subjects of the empire 1c) the whole inhabited earth, the world 1d) the inhabitants of the earth, men 2) the universe, the world
οἰκουμένη
oikoumenē
oy-kou-men'-ay
Feminine participle present passive of G3611 (as noun, by implication of G1093); land, that is, the (terrene part of the) globe; specifically the Roman empire
G1774 ἐνοικέωἐνοικέω
enoikeō
en-oy-keh'-o
From G1722 and G3611; to inhabit (figuratively)
KJV Usage: dwell in.
G2730 κατοικέωκατοικέω
katoikeō
kat-oy-keh'-o
From G2596 and G3611; to housepermanently, that is, reside (literally or figuratively)
KJV Usage: dwell (-er), inhabitant (-ter).
G3610 οἰκέτηςοἰκέτης
oiketēs
oy-ket'-ace
From G3611; a fellow resident, that is, menial domestic
KJV Usage: (household) servant.
G3612 οἴκημαοἴκημα
oikēma
oy'-kay-mah
From G3611; a tenement, that is, (specifically) a jail
KJV Usage: prison.
G3613 οἰκητήριονοἰκητήριον
oikētērion
oy-kay-tay'-ree-on
Neuter of a presumed derivative of G3611 (equivalent to G3612); a residence (literally or figuratively)
KJV Usage: habitation, house.
G3939 παροικέωπαροικέω
paroikeō
par-oy-keh'-o
From G3844 and G3611; to dwellnear, that is, reside as a foreigner
KJV Usage: sojourn in, be a stranger.
G4039 περιοικέωπεριοικέω
perioikeō
per-ee-oy-keh'-o
From G4012 and G3611; to residearound, that is, be a neighbor
KJV Usage: dwell round about.
G4924 συνοικέωσυνοικέω
sunoikeō
soon-oy-key'-o
From G4862 and G3611; to residetogether (as a family)
γῆ
gē
ghay
Contracted from a primary word; soil; by extension a region, or the solid part or the whole of the terrene globe (including the occupants in each application)
G508 ἀνώγεονἀνώγεον
anōgēon
an-ogue'-eh-on
From G507 and G1093; above the ground, that is, (properly) the secondfloor of a building; used for a dome or a balcony on the upper story
KJV Usage: upper room.
G1069 γείτωνγείτων
geitōn
ghi'-tone
From G1093; a neighbor (as adjoining one’s ground); by implication a friend
KJV Usage: neighbour.
G1092 γεωργόςγεωργός
geōrgos
gheh-ore-gos'
From G1093 and the base of G2041; a landworker, that is, farmer
KJV Usage: husbandman.
G1919 ἐπίγειοςἐπίγειος
epigeios
ep-ig'-i-os
From G1909 and G1093; worldly (physically or morally)
KJV Usage: earthly, in earth, terrestrial.
G2449 ἸουδαίαἸουδαία
Ioudaia
ee-oo-dah'-yah
Feminine of G2453 (with G1093 implied); the Judaean land (that is, judaea), a region of Palestine
KJV Usage: Juda.
G4066 περίχωροςπερίχωρος
perichōros
per-ikh'-o-ros
From G4012 and G5561; around the region, that is, circumjacent (as noun, with G1093 implied, vicinity)
KJV Usage: country (round) about, region (that lieth) round about.