Somebody have something on the tip of his/her tongue
Contexto
When you have a word on the tip of your tongue it's recommended that you look it up rather than keep searching your brain's clumsy filing system. Neuroscientists studying brain activity have found that the filing system in our brains is more like a messy desk piled high with papers than an orderly filing cabinet. ‘Tip-of-the-tongue’ moments, or ‘TOTs’, occur when we know where the paper (or word) that we are looking for is, but can’t find it right away