The Disassociate from Geometry option allows you to disassociate the selected edge, surface or face that is associated to the geometry.
The selection of different entities to be disassociated can be done individually or together.
Note: Any association can be removed (associated to nothing), however, you can easily overwrite associations without disassociating first. For instance, if an edge is associated with a curve, you can directly associate it with a surface, you do not need to first disassociate it.