Available Liferay 7.4 U26+ and GA26+
You can delete draft and published object definitions. Deleting a definition removes its associated data, including the stored entries for published definitions.
For versions before Liferay 7.4 U26/GA26, users cannot delete published object definitions.
If a definition has active relationships, you must remove them before you can delete the definition. See Removing Relationships for more information.
To delete the definition,
Open the Global Menu (), go to the Control Panel tab, and click Objects.
Click the Actions button () for the desired definition and select Delete.
In the dialog window, enter the name of the definition and click Done to confirm.