Sometimes the brain just clams up. I've been asking it to give me a word. It's a word I'm perfectly familiar with. I've been trying to get at it for half an hour or more and I haven't yet come close. I think it has "chron" in it somewhere. It's the word that means sort of you know when you're writing historical fiction and you stick in something modern that couldn't possibly have existed back then. Like in Deadwood last night where our noble but quick-tempered hero spent half a day over the funeral rites for the injun he just killed. Like that would so have happened in the 1870s!
Come on brain!
One technique for dealing with the problem is to walk away whistling, then circle back undercover and pounce. Take the brain off guard. I've been trying that. And it hasn't worked....
...Hey I've got it! I'll tell you what I did. I decided to Google "historical fiction" and hope that I'd find a text containing my word. And before I'd done more than type an "h" and an "i" the brain had surrendered and handed over the goods. It quails before the power of Google. It knew the game was up.