certifiably

With the potential for certification.

Was the accused at the time of the commission of the act with which he is charged, and before that time, laboring under such mental disease as to render him certifiably insane? […] He goes on to ask, How is a jury to determine whether a man is " certifiably insane?" How is any man to attach a definite meaning to "certifiably insane?" "The phrase can only mean that a couple of doctors can be found to certify that in their opinion the man is insane."

Must such a neighborhood or district maintain a certain percentage of certifiably ethnic residents to maintain its eligibility?

Genuinely

The main purpose for California Certified Organic Farmers is to certify that the products that growers are selling are certifiably organic

To a great extent.

He is certifiably nuts

Due mostly to his latest creation, the whacked-out Guggenheim branch that opened this fall in Bilbao, Spain, the 68-year-old Gehry has gone from being tagged the scary cousin in architecture's dysfunctional family to being certifiably huge.

Undoubtedly, demonstrably.

The Tofu Cheesecake Bake-Off, which ten daring bakers had entered, was a special event held mid-week. It was, certifiably, the world's first such tofu pie contest

You can get a long way into the Presley or Lennon mythology before you have to worry about the way these certifiably electric personalities dealt with the vocal problems of a particular phrase