RENDERS SENSELESS is a phrase that describes the act of making someone or something unable to think or act in a rational manner. The crossword solutions KAYOS and STUNS are both five-letter words that can be used to describe this action. KAYOS is an informal term for a knockout, which is when a person is rendered unconscious by a physical blow. STUNS is a verb that means to shock or surprise someone so much that they are temporarily unable to think or act. Both of these words can be used to describe the act of rendering someone or something senseless.