The term neoliberalism first appeared in 1898 as a pejorative for neoclassical economics.

Evidence

Actually, the term is considerably older. The first recorded usage (according to the Oxford English Dictionary) dates from 1898, when it was used by the co-operative economist Charles Gide to describe, in a somewhat pejorative manner, the neoclassical economics of Maffeo Pantaleoni. — Philip Mirowski & Dieter Plehwe (eds.), The Road from Mont Pèlerin, 2092

Categorization

• XREF: Connects to the reader’s study of foundational neoliberalism historiography — the term’s much earlier origin than its common association with the Mont Pèlerin network. — connects to: The term neoliberalism was coined at the 1938 colloquium on a cartelist’s suggestion — Quinn Slobodian, Globalists: The End of Empire and the…, 267; The term ‘neoliberalism’ was championed in 1939 by French industrialists and economists — Dieter Plehwe, Quinn Slobodian & Philip Mirowski (eds.), Nine Lives of Neoliberalism, 382; The term ‘neoliberalism’ was coined at the 1938 Colloque Walter Lippmann — Philip Mirowski & Dieter Plehwe (eds.), The Road from Mont Pèlerin: The Making…, 775 (+1 more)
• DEFINE: Clarifies the etymology and earliest recorded sense of ‘neoliberalism’ via the OED.