What is an antonym for hyphen?

There isn't a direct antonym for "hyphen" in the sense of a word with the opposite meaning. However, depending on the context, you could use these terms:

If referring to the punctuation mark:

* Space: A space is the opposite of a hyphen in terms of joining words.

* Comma: A comma can separate words or phrases, which is the opposite of a hyphen's function.

If referring to the concept of combining words:

* Separation: Instead of combining words, you could separate them with a space or other punctuation.

* Individuality: You could use individual words instead of a hyphenated word.

The best way to find the appropriate alternative depends on the specific situation and the intended meaning.