Mu can be:
Mu , ? or ?, a letter in the Greek alphabet pronounced "mew" (//). ? is used as a symbol for:
The SI prefix micro, denoting a factor of 10−6 (one millionth).
? by itself is often used as the "unit" of strain, though in this context it retains its SI prefix meaning, which is interchangeable with "x 10−6" or "ppm" (parts per million).
? by itself is a deprecated abbreviation for the deprecated unit micron. The preferred terms are µm and micrometre
In mathematics,
The arithmetic mean of a statistical population
The Möbius function
The least-fixed-point-operator
A degree of membership from a fuzzy set.
In chemistry,
The chemical potential
In physics,
The coefficient of friction
The mobility coefficient
The permeability coefficient
The muon, an elementary particle
The standard gravitational parameter
The magnetic dipole moment
The linear density
Viscosity
Reduced mass
µTorrent, a freeware BitTorrent client for Microsoft Windows written in C++.
?
Source:
http://en.wikipedia.org/wiki/MU