ill-formed Get Printable Handwriting Hear It! Say It! Write It! Learn It! Spelling Test Definition adjective. not correctly structured or shaped. Example Sentence Some of the punctuation in her essay was ill-formed. More Example Sentences His argument was ill-formed and confusing. Synonyms incorrect; malformed; awkward Antonyms well-formed; correct; proper Hear It! Say It! Write It! ill-formed Switch to cursive Start Share with your friends: