# UNDEFINE Command [GstarCAD 2027](Help%20System/GSTARCAD/2027/Index.md) → [Commands](Help%20System/GSTARCAD/2027/Commands/(Commands).md) → [U](Help%20System/GSTARCAD/2027/Commands/U/(U).md) ## Function Description: This command is used to allow the command defined by the application to replace the internal command. Users can forbid a command by entering the command name under the UNDEFINE command prompt. The forbidden command can be redefined to execute other functions. ## Command Access: > **Icon:** / > **Menu: /** > **Ribbon: /** > **Toolbar: /** > **Command:** UNDEFINE > **Alias:** / ## Command Prompts: ``` Enter command name: ``` --- **Related References：** - [Commands about Customization (GstarCAD 2026)](../../../2026/Commands/00%20Command%20Groups/Commands%20about%20Customization.md) --- [Original help](https://www.gstarcad.net/help/GstarCAD_2027_en-US/detail/commandReferences_U/UNDEFINE.html) · © Gstarsoft Co., Ltd.