requirement

Something you need or must do before something else can happen.

• A driving licence is a job requirement.
• Do you meet the age requirement?
• Applicants must satisfy all entry requirements.

How to use it: requirement for something (A passport is a requirement for this trip.)

Similar words: necessity, condition, prerequisite

Common phrases: meet a requirement, minimum requirement, entry requirement, legal requirement

A written rule describing what a system or product must do to be accepted.

• Each requirement must be tested.
• The software meets every functional requirement in the document.
• Engineers changed the design to satisfy a new safety requirement.

Similar words: specification, constraint

Common phrases: functional requirement, system requirement, technical requirement, requirement specification

Something that someone asks another person to provide or do.

• The king made a requirement of his guests.
• Her only requirement was that he write to her.
• He refused to answer the messenger's requirement.

Similar words: request, demand

Common phrases: make a requirement, answer a requirement, someone's requirement