The unhyphenated form antisemitism reflects that Semitism never existed as a phenomenon.

Evidence

The prevailing convention is not to use a hyphen in antisemitism as no phenomenon such as Semitism has ever existed (even though there is a racial-linguistic genealogy of Semites which some trace to Noah’s son Shem, and of course this includes Muslims too; see Firestone 2011). — Nasar Meer, Racialization and Religion, 63

Categorization

• DEFINE: Explains the spelling convention antisemitism vs anti-Semitism and the rationale behind it.
• CANDY: A neat etymology-style fact about why the hyphen is dropped that makes for easy conversational trivia.
• XREF: Connects to the reader’s broader knowledge of antisemitism/Islamophobia discourse in this book and to the Semitic language family. — connects to: Debates over whether anti-Zionism constitutes antisemitism come in qualitative and quantitative forms. — Nasar Meer, Racialization and Religion: Race,…, 56