Hi Masi,
Sorry for the delay in response.
If you are referring to delete the PDF form in Adobe Acrobat Reader on your iOS device, refer to the steps mentioned in the following link for "Deleting Files".
Adobe Reader Help for iOS: Copying, editing, deleting, and other file and folder actions
Check if that is what you looking for.
Let us know if you are referring to something else.
Regards,
Meenakshi