What does the prefix "inter-" signify in medical terms?

The prefix "inter-" in medical terminology signifies "between." This prefix is commonly used to describe relationships or connections involving two or more entities or structures. For instance, in terms like "interstitial," referring to the spaces or fluid that exist between cells, or "intercostal," which pertains to the muscles located between the ribs, the prefix emphasizes the idea of something being in the space or position among or between other parts.

The other prefixes do not convey this meaning; "one" typically relates to singularity, "beyond" refers to surpassing or going past, and "small" indicates a diminutive size. Therefore, "inter-" is specifically associated with relationships that occur in the space between distinct or separate entities.