What is the act of saying or writing something again called?

The correct answer is the term "reiteration," which refers specifically to the act of stating or writing something again for clarity or emphasis. While "repetition" is closely related and implies doing something over again, it does not necessarily emphasize the intent of clarity or restatement that "reiteration" does.

Reiteration is often used in contexts where a point needs to be stressed or made clearer, distinguishing it from other terms that have slightly different connotations. For instance, "recapitulation" tends to refer to summarizing the main points rather than restating them verbatim, and "revision" typically involves making changes or improvements rather than simply restating the same content. Therefore, "reiteration" captures the essence of restating something accurately and purposefully.