1. Capability of two or more items or components of equipment or material to exist or function in the same system or environment without mutual interference.
2. In computing, the ability to execute a given program on different types of computers without modification of the program or the computers.
3. The capability that allows the substitution of one subsystem (storage facility), or of one functional unit (e.g. , hardware, software), for the originally designated system or functional unit in a relatively transparent manner, without loss of information and without the introduction of errors.
Source: from Federal Standard 1037C and from MIL-STD-188 and from the Department of Defense Dictionary of Military and Associated Terms
wikipedia.org dumped 2003-03-17 with terodump