To delete a form, check the box next to the form on the "Forms" page of your account. Then click on the button that says "delete" with a trash can icon.
A warning message will pop up to make sure you really want to delete your form. At this point, hit the "Delete" button or the Cancel button.
Re-using a Deleted Form's URL
When a form is moved to the Deleted Forms folder the URL attached to that form is still not free to use on a live form. You will either need to wait 7 days until the form has been hard deleted from your account or restore the form, change the URL from the Settings page, then delete the form again.
Restore a Deleted Form
If you accidentally delete a form, you will have 7 days to restore it. You can find deleted forms by clicking on the "Deleted Forms" link on the left side of your list of forms.
To restore a form, check the box next to the form on the "Deleted Forms" page of your account. Then click on the button that says "restore" with an arrow icon. This will reactivate your form and move it back to your list of Active forms.