forbidden definition : not allowed by law or rules. Check meanings , examples, usage tips, pronunciation, domains, and related words. Discover expressions like " forbidden fruit", " forbidden territory", "the forbidden fruit tastes the sweetest". The meaning of FORBIDDEN is not permitted or allowed . How to use forbidden in a sentence. forbidden Definition , Meaning & SynonymsIt is forbidden to smoke in the building. The treasure was hidden in a forbidden cave. She felt drawn to the forbidden fruit of knowledge. Your All-in-One Learning Portal: GeeksforGeeks is a comprehensive educational platform that empowers learners across domains-spanning computer science and programming, school education, upskilling, commerce, software tools, competitive exams, and more.