Chemical caustic is a term used to describe a range of substances that are corrosive and can cause chemical burns. The crossword solutions for this term include nitric (6 letters), LYE (3 letters), ACID (4 letters), lyes (4 letters), and ALKALI (6 letters). Nitric is a strong oxidizing ACID, LYE is a type of alkaline solution, ACID is a sour-tasting substance, lyes are a type of caustic ALKALI, and ALKALI is a type of base. All of these substances are considered caustic chemicals and can be dangerous if handled improperly.