When it comes to describing someone who is consistently inactive or seemingly uninterested in doing anything worthwhile, one might use the phrase "lazy bones." However, if you're looking for some synonyms to mix up your vocabulary, there are plenty of options. You might call someone a slacker, sluggard, loafer, or layabout. Other possibilities include couch potato, underachiever, procrastinator, and do-nothing. Of course, some people might take offense at being labeled in this way, so it's important to use these terms with care and consideration. But if you're in the mood for some playful banter with a lazy friend or coworker, these options are sure to come in handy.