Catholics coming out of a lunchtime Mass at Erie's St. Peter Cathedral weren't familiar with "ineffable."
What? Nobody (no ‘girls’ of a certain age, at least) read Love Story? Love Story, the 1970’s cheese phenom? I never thought I’d find a need to quote Love Story, but if my recall is accurate that book expanded my vocabulary beyond my ability to read obscenities out loud in Public Speaking. (that is a whole ‘nother story) So, anyway, Oliver comes home from work and finds Jennifer “ineffably” sad. The right word. Precisely right. And if it works with Love Story-struck ninth graders I think the comprehension bar has been set with appropriate restraint.

Via Whispers in the Loggia I read of Erie Bishop Donald Trautman’s
devaluation of the popular intellect in regards to the translation of the Roman Missal. He said the draft includes words such as "ineffable" that would not be in the ordinary vocabulary of people.

”We should certainly have elevated tone, but words like that are just beyond the common comprehension." So, Your Excellency, you’re saying ineffable is incomprehensible. They’re sort of vocab cousins, aren’t they?