INTERNAL definition: 1. inside the body: 2. inside a person's mind: 3. inside an object or building: . Learn more. The adjective internal describes something on the inside. If you're tempted by a second piece of cake, you may have an internal battle with yourself over whether you should eat the cake or not. 7 meanings: 1. of, situated on, or suitable for the inside; inner 2. coming or acting from within; interior 3. involving the.... Click for more definitions. Master the word " INTERNAL " in English: definitions, translations, synonyms, pronunciations, examples, and grammar insights - all in one complete resource.