Mammoth Cave

Mammoth Cave, a cave in Kentucky, U.S., about 10 m., the largest in the world, and rising at one point to 300 ft. in height, with numerous side branches leading into grottoes traversed by rivers, which here and there collect into lakes; name also of another of smaller dimensions in California.

Definition taken from The Nuttall Encyclopædia, edited by the Reverend James Wood (1907)

Mammoth * Man, Isle Of
[wait for the fun]
Malpighi, Marcello
Malström
Malta
Maltebrun, Conrad
Malthus, Thomas R.
Malvern, Great
Mambrino
Mamelukes
Mammon
Mammoth
Mammoth Cave
Man, Isle Of
Man of Destiny
Man of Feeling
Man of Ross
Man of Sin
Manasseh-ben-Israel
Manby, Captain
Mancha, La
Manche, La
Manchester