"Mu" is the correct answer to the classic trick question "Have you stopped beating your wife yet?". Assuming that you have no wife or you have never beaten your wife, the answer "yes" is wrong because it implies that you used to beat your wife and then stopped, but "no" is worse because it suggests that you have one and are still beating her. According to various Discordians and Douglas Hofstadter the correct answer is usually "mu", a Japanese word alleged to mean "Your question cannot be answered because it depends on incorrect assumptions".
Hackers tend to be sensitive to logical inadequacies in language, and many have adopted this suggestion with enthusiasm. The word "mu" is actually from Chinese, meaning "nothing"; it is used in mainstream Japanese in that sense, but native speakers do not recognise the Discordian question-denying use.
Thanks to Thrakem for the source of this definition.
A monk asked Joshu, "Does a dog have the Buddha nature?"
Joshu retorted, "Mu!"
(1) the principal of a school or similar educational institution
(2) someone who is really good at oral sex
I got sent to the headmaster.
A bastardization of the term 'wicky,' which, in turn, is a bastardization of the term 'wicked,' which means about as much as cool, funny, relaxed, etc.
A seriously wickee guy.
This Is Africa, Baby (acronym
Used by disgruntled westerners anywhere in Africa in response to any complaint of something not working properly, being bad, etc.
X: "The power was off for 48 hours in our home!"
Y: "What do you expect? TIAB."