Simply remove the data object from Adapter of your ListView. Which item to remove can be found from internalPosition. Check below code for how to find internalPosition.
@Override
public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo) {
super.onCreateContextMenu(menu, v, menuInfo);
AdapterView.AdapterContextMenuInfo info = (AdapterView.AdapterContextMenuInfo) menuInfo;
final int internalPosition = info.position;
}