Greater Finland means Finland including territories of Finnish kindred peoples (Finnic people): Finns, Karelians, Estonians, Ingrians.
Commonly it contains so called natural borders, which go from White Sea to Lake Onega and along River Svir and River Neva or River Rajajoki to Gulf of Finland. Those borders include Finns and Karelians. Sometimes is included also Ingria and Estonia.
The most extended borders include northern Finnmark and western Torne Valley and all area to eastern Ural Mountains or even more easter.
History
Ideology of Greater Finland come from 19th centurys Karelianism.