Mid 17th century; earliest use found in John Sadler (1615–1674), political theorist and reformer. From classical Latin ad extremum at or to the end from ad at, to + extrēmum (accusative), use as noun of neuter of extrēmus.
Definition of ad extremum in US English:
ad extremum
adverb
To the ultimate extent or degree; excessively.
Origin
Mid 17th century; earliest use found in John Sadler (1615–1674), political theorist and reformer. From classical Latin ad extremum at or to the end from ad at, to + extrēmum (accusative), use as noun of neuter of extrēmus.