[Home](./index.md) > [kibana-plugin-plugins-expressions-server](./kibana-plugin-plugins-expressions-server.md) > [ExpressionAstFunctionBuilder](./kibana-plugin-plugins-expressions-server.expressionastfunctionbuilder.md) > [removeArgument](./kibana-plugin-plugins-expressions-server.expressionastfunctionbuilder.removeargument.md) ## ExpressionAstFunctionBuilder.removeArgument property Removes an (optional) argument from the function. TypeScript will enforce that you only remove optional arguments. For manipulating required args, use `replaceArgument`. Signature: ```typescript removeArgument: >>(name: A) => this; ```