What prefix generally indicates "partial" or "half"?

The prefix that indicates "partial" or "half" is "hemi-." This prefix is derived from the Greek word "hemisus," which means half. It is commonly used in medical terminology to describe conditions or anatomical structures that are associated with half or a part of something, such as "hemiplegia," which refers to paralysis of one side of the body.

The other prefixes do not convey the meaning of "partial" or "half." For example, "tetra-" means four, "multi-" implies many, and "tri-" signifies three. Each of these prefixes has a distinct numerical connotation that is unrelated to the notion of part or half. Therefore, "hemi-" stands out as the appropriate choice for indicating "partial" or "half."