You may use landmass
Merriam Webster
landmass:
a large area of land
continental landmasses
Three examples plucked at random from the web are:
Geography
Geographically, the Kola Peninsula forms the heel of the Scandinavian landmass
Wikipedia
Albania has a variety of climate systems. With its coastline facing the Adriatic and Ionian seas in the Mediterranean sea, its highlands backed upon the elevated Balkan landmass, ...
DSFL
Korean (Hankukmal) is the language of the Korean landmass in upper east Asia.
In each example the area referred to comprises more than one country but does not extend to a whole continent, although the term is also used for that purpose.