decertify

To annul the certification of.

The American Medical Association (AMA) was formed in 1845 to gain for medical doctors a monopoly on legal licensure as health practitioners. The young AMA waged fierce (and quite successful) battles to de-certify the then-dominant natural healers — a range of herbalists, midwives, and homeopathic doctors.

Nigeria was tagged as a transit-route of drug carriers. This prompted the United States government to decertify the country.

To annul a labor union.

As Sallas immediately said, the 130 scabs who so easily replaced the striking printers in '85 won't be foisted upon the union--to degrade it and possibly decertify it.