Aberratory

There was enough of her family in Fedora for that last to sound improbable—another of those things to be assuaged, a sort of unaccountable temperamentality; not as bad as a drug addict but impolitely aberratory.

Source: wiktionary

This was so acceptable an improvement on either “King Caucus” or the erratic and aberratory method of legislative or mass-meeting nominations that the parties adopted it for the Presidency as well as the Vice Presidency.

Source: wiktionary