Removes the crease from selected mesh faces, edges, or vertices.

Button
Ribbon: Mesh tab
Mesh
panel
Remove
CreaseNot available on the ribbon
in the current workspace
Menu: Modify
Mesh
Editing
UncreaseNot available in menus
in the current workspace
Toolbar: Smooth
Mesh
Restore smoothness to an edge that has been creased.

You can also remove a selected crease in the Crease area of Properties palette by changing the Type value to None.