noun, masculine/fɔʁ.ma.lism/plural: formalismes
formalisme is masculine in French.
formalism
“Le lourd formalisme exigé des éventuels plaignants et l’amende prévue en cas de dénonciation inexacte, rendent ce texte inopérant.” — The heavy formalism required of potential complainants and the fine provided for in the case of a false accusation, renders this text ineffective.
From Latin fōrmālis (whence French formel) + -isme.