What suffix is used to indicate something that is "pertaining to"?

The suffix that indicates "pertaining to" is commonly represented by -ic. This suffix is widely used in the medical terminology context to form adjectives that describe a relationship to a particular subject or entity. For example, "gastric" pertains to the stomach, and "muscular" refers to muscles.

While -ac and -ous also denote a similar meaning of "pertaining to," they are less commonly recognized as the primary suffix for this definition within the medical terminology framework. The suffix -ia typically denotes a condition or state, and while it is integral to creating medical terms, it does not express the notion of being "pertaining to" in the same way. Thus, -ic stands out as the most appropriate choice for this context, making it the favored suffix that indicates a relationship or pertains to a specific aspect in medical language.