The term 'Something Harmful' can be summed up by the crossword solution of 'POISON' (6 letters). POISON is a substance that can cause harm or death to living organisms, and has been used for centuries as a weapon or tool of murder. It can be found in nature, created synthetically, or even administered accidentally. POISON can be ingested, inhaled, or absorbed through the skin, and its effects can range from mild to fatal.