Base

A base is:

A number that is raised to a power, or base of an exponential function. This finds common use, for example, in the depiction of numbers, for instance, 10 is the base used in the decimal system, whereas 2 is the base in the binary system. See also numeral system and radix
The base of a logarithmic function.
One of the parallel sides of a trapezoid or the unequal side of an isosceles triangle.
In topology, a base (topology) for a topology is a set of open sets such that every element of the topology is a union of the base sets. See also subbase.
Base of a transform in mathematics
In biochemistry, see nitrogenous base.
In baseball, a base is one of 4 bags placed at corners of the infield diamond that a player has to run to after hitting the ball.
In a transistor the base is the controlling connection to the junction.
In Marxism describes the material equipment and material relations of human society, as distinct from the 'superstructural' forms of society - laws, customs, ideas, beliefs, etc.
BASE jumping is a popular variation on skydiving.
The name of the terrorist group Al-Qaida translates as "the base."
In 2001, the catchphrase "All your base are belong to us" swept across the Internet.
In chemistry, a base is the reactive complement to an acid. (Sometimes the term alkali has been used historically where base is now preferred.) See Acid-base reaction theories. Technically, a substance capable of neutralizing acid, with a pH greater than 7.0. See Table of bases
Base is also an isolated settlement in inhospitable conditions that must rely on outide help in order to survive, such as military base, Antarctica base, Moon base.