semicolon
A programmer's bane. Required by most programming langauges to seperate commands. The semicolon will usually render an entire program useless and force the programmer to search every line for that goddamn semicolon.
Example:
Programmer: I wrote a program to find the answer to life, the universe, and everything and I left out a semicolon! Fjsk!
Programmer: I wrote a program to find the answer to life, the universe, and everything and I left out a semicolon! Fjsk!