Here are some examples:
* Dichotomy: A division into two parts
* Dioxide: A compound containing two oxygen atoms
* Diploma: A document signifying completion of two years of study
* Disaccharide: A sugar composed of two monosaccharide units
* Dichromatic: Having vision with only two primary colors
It's important to note that the prefix "-di" can sometimes have other meanings, depending on the context. For instance, in some cases, it can indicate double or two-fold.
If you encounter a word with the "-di" prefix, it's always a good idea to look up its meaning in a dictionary to be sure.