lye soap Get Printable Handwriting Hear It! Say It! Write It! Learn It! Spelling Test Definition noun. a type of soap made using lye and fats. Example Sentence My grandfather uses lye soap. More Example Sentences Many people enjoy making lye soap. Synonyms cleanser; detergent; soap Antonyms dirt Hear It! Say It! Write It! lye soap Switch to cursive Start Share with your friends: