draw a blank

dar branco (mas atente que em inglês você "sorteia" ou "tira" um blank; não achar a resposta.

Okay, so I'm drawing a blank on this question! Help!

Do you remember how to say that word in Spanish?" - "I'm drawing a blank."

"I'm sorry, but I am drawing a blank on your name."

I was tired and drew a blank when Mr.Right asked for an answer.

2.sortear um bilhete não premiado

This book gives the names of the participants and whether they drew a blank or a prize.

He was persuaded by a friend to invest the whole amount in lottery tickets, every one of which drew a blank, leaving him penniless.

I don't even play the loto any more, I just draw blanks.

origin of the expression