A more thorough explanation:

A half nephew is the son of one's half brother or half sister. This means that they share only one biological parent with the person in question.

For example, if John has a half brother named Tom, and Tom has a son named Jack, then Jack is John's half nephew.

Historically, the term "half nephew" was also used to refer to a grandchild or any descendant. However, in modern usage, it specifically refers to the son of a half sibling.

It's important to note that a half nephew is different from a nephew, who is the son of one's full brother or sister.

For example, if John has a full brother named Mike, and Mike has a son named Joe, then Joe is John's nephew.