John has a daily calendar of Forgotten English. Yesterday's word was Opiniatrety. It is defined in the calendar as "Unreasonable attachment to one's own notions".
I can't imagine why that word has fallen from favor.
And while I'm waxing on all things grammatical, should one say "Yesterday's word was ..." or "Yesterday's word is...". Because it refers to an entry on a calendar, the word for March 22 is Opiniatrety, but March 22 was yesterday. Hmmmm.