Quasi- is a prefix meaning “seeming like” or “almost, but not quite.” It attaches to words to show that something resembles or partially fits a category without fully belonging to it.

A quasi-experiment in science looks like a real experiment but doesn't have all the controls that a true experiment requires. A quasi-official statement seems official but wasn't formally approved. When someone acts in a quasi-parental role, like an older cousin watching younger kids, they're doing parent-like things without actually being a parent.

The prefix often appears in more formal or academic contexts. You might read about a quasi-governmental organization that works closely with the government but isn't technically part of it, or a quasi-religious ceremony that has spiritual elements without being connected to any particular religion.

Think of quasi- as the “kind of” or “sort of” prefix. It acknowledges similarity while maintaining an important distinction. When you spot this prefix, you know the writer is being precise about something that's close to, but not exactly, what the main word describes.