1. All actions taken to ensure that standards and procedures are adhered to and that delivered products or services meet performance requirements.
2. The planned systematic activities necessary to ensure that a component, module, or system conforms to established technical requirements.
3. The policy, procedures, and systematic actions established in an enterprise for the purpose of providing and maintaining a specified degree of confidence in data integrity and accuracy throughout the lifecycle of the data, which includes input, update[?], manipulation, and output.
Source: from Federal Standard 1037C and from MIL-STD-188
This is also the meaning in software engineering.
Software engineering Software testing
wikipedia.org dumped 2003-03-17 with terodump