When it comes to synonyms for the word "showboat," there are plenty of options to choose from. For instance, you could use terms like "braggart," "boaster," or "swaggerer" to describe someone who is showing off excessively. Additionally, words like "ostentatious," "flashy," or "flamboyant" could be used to describe an object or action that is done with the intention of drawing attention or impressing others. Other potential synonyms for "showboat" might include words like "grandstander," "exhibitionist," or "attention-seeker," all of which can be used to describe individuals who crave the spotlight and are always looking for ways to make a splash.