Requisite \REK-wuh-zit\ (adjective) - Required by the nature of things or by circumstances; indispensable. (noun) - That which is required or necessary; something indispensable. "Birth is not a requisite. If it were, the golden fold would be composed of young people still in their teens... Brains are not a requisite either." -- Edgar Saltus, 'The Pomps of Satan' Requisite derives from Latin requisitus, past participle of requirere, "to require."