The term "threeline head" implies a concise and informative header that consists of three lines of text. In essence, it serves as a summary or introduction to a certain topic. If you're looking for synonyms for this phrase, you can consider using alternatives like "triple-line heading", "three-line title" or "compact header". These expressions capture the essence of a brief but effective headline that grabs attention and conveys crucial information. By using compelling and precise language within the limited character space, a threeline head can successfully convey the main idea, enticing readers to delve deeper into the subject matter.