neologisms - Word for someone ignorant of, but not expected to be knowledgeable about, something

A discussion arose in our office which brought about remembrance of an old term used by William F. Buckley, Jr. — from his old National Review days — in his "Word of the Day." We can't find the term on the Interwebs, so we come to SE:ELU in hopes of enlightenment.

The definition, as we recall is:

"Being ignorant of something of which you have neither reason nor expectation to have any knowledge."

I'd really like a reference to Buckley's WotD if possible since it will be used frequently in my geek- and academic-heavy office!

Answer

I think I may have found the term the OP is searching. It is without doubt a word I have never heard of before. It's worth citing the entire Wikipedia article

Ultracrepidarianism

Ultracrepidarianism is the habit of giving opinions and advice on matters outside of one's knowledge.

The term ultracrepidarian was first publicly recorded in 1819 by the essayist William Hazlitt in an open Letter to William Gifford, the editor of the Quarterly Review: "You have been well called an Ultra-Crepidarian critic." It was used again four years later in 1823, in the satire by Hazlitt's friend Leigh Hunt, Ultra-Crepidarius: a Satire on William Gifford.

The term draws from a famous comment purportedly made by Apelles, a famous Greek artist, to a shoemaker who presumed to criticise his painting. The Latin phrase "Sutor, ne ultra crepidam", as set down by Pliny and later altered by other Latin writers to "Ne ultra crepidam judicaret", can be taken to mean that a shoemaker ought not to judge beyond his own soles. That is to say, critics should only comment on things they know something about. The saying remains popular in several languages, as in the English, "A cobbler should stick to his last", the Spanish, "Zapatero a tus zapatos", the Dutch, "Schoenmaker, blijf bij je leest", and the German, "Schuster, bleib bei deinem/deinen Leisten" (the last two in English, "shoemaker, stick to your last")