There are plenty of synonyms for "half done," depending on the context in which the phrase is used. You could say something is "partially completed," "half-finished," "incomplete," "unfinished," or "partway done." These options all imply that there is more work to be done to bring a project or task to its completion. Similarly, you might describe something as "half-baked" if it lacks the necessary depth or attention to detail. On the other hand, if an activity is undertaken without sufficient preparation or effort, you could describe it as "half-assed." Regardless of the phrasing, it's clear that "half done" suggests that something falls short of being truly finished or complete.