Halfsies is a slang term used to describe a situation where two people or parties evenly split something. However, the term "halfsies" is informal and may not be appropriate for all settings. Therefore, there are several other synonyms that can be used to express the same meaning. These include "split down the middle," "divided equally," "even-steven," "50/50," "shared," or "divvied up." Using these alternatives can help you communicate the concept more effectively and professionally in different contexts. So next time when you need to describe a situation where something is split equally, consider using one of these synonyms instead of halfsies.