Answer:

isthmi

Answer	Crossword Clue
ISTHMI	Extended land masses
ISTHMI	Panama and Suez
ISTHMI	Thin land masses

ISTHMI	Cartographic connectors
ISTHMI	Continental connectors
ISTHMI	Connecting strips of land
ISTHMI	Narrow land formations
ISTHMI	Strips in the water?
ISTHMI	Necks in the water?
ISTHMI	Strips near the water
ISTHMI	Narrow strips of land

ISTHMI	Topographical necks
ISTHMI	Necks of land.
ISTHMI	Panama and Corinth.
ISTHMI	Suez and Panama.
ISTHMI	Necks of land
ISTHMI	They're bicoastal
ISTHMI	Strips on a map
ISTHMI	Panama and others

ISTHMI	Thin strips
ISTHMI	Connecting strips
ISTHMI	Panama and Kra
ISTHMI	Land mass connectors
ISTHMI	Connecting strips of land (Var.)
ISTHMI	Land mass connectors (Var.)
ISTHMI	Panama Suez and Corinth
ISTHMI	Fingers of land

ISTHMI	Panama and Corinth
ISTHMI	Slender land masses