You can delete an address from the address book. To do so, click the delete icon, in the rightmost column of the address list.
A pop-up window will ask you to confirm the deletion.
If the address is used in upcoming whereabouts calendars, a dialog will remind you that future whereabouts entries will also be deleted. Click yes to delete all upcoming whereabouts entries using this address, or click Cancel to abort the deletion of the address. Past whereabouts entries cannot be deleted.