markotoole (noun)
The name of a person, place, object, a fact – or anything, really! – that you're absolutely certain you once knew and it’s on the tip of your tongue, but you can’t for the life of you remember it… Until you finally give up and ask someone, look it up in a book or online, or simply allow your brain to stop trying to recall it. Then, weirdly, it’ll hit you like a bolt of lightning. So called because, in pre-internet days, we spent half an hour desperately trying to think of the name of the bassist in Frankie Goes To Hollywood. Then, as one of us was halfway through dialling a relative to ask, the other blurted out, “Mark O’Toole!”
(PS We accept that The Meaning Of Liff or one of its predecessors may already have a word for this, but this is what we call it. So there!)