The very word secularism was a strategic euphemism devised by Victorian freethinkers

Evidence

The terms “secularism” and “secularist” were introduced into English by freethinkers in the middle of the nineteenth century in order to avoid the charge of their being “atheists” and “infidels,” terms that carried suggestions of immorality in a still largely Christian society. — Talal Asad, Formations of the Secular, 92

Categorization

• QUESTION: This etymological origin — secularism as a self-protective euphemism aimed at remaining respectable within a Christian moral order — is a sharp lever against Cooper-style claims that secularism is a neutral frame; worth chasing whether 19th-century usage retained a Christian-protest flavor.
• DEFINE: Defines secularism by its strategic discursive origins rather than any substantive ideology.
• CANDY: Neat trivia: the word secularist was invented to dodge accusations of atheism in Christian England.