Approximately this size. Said while using one's fingers, hands, or arms to visibly demonstrate size. "I'll have a small glass of wine, only yay big," he said, holding his thumb and index finger about an inch and a half apart. A: "You were only yay big the last time I saw you!" B: "I was 11, Uncle Jerry. There's no way I was only up to your hip." Fish have to be about yay big for you to keep them, she said, putting her hand up to her sternum.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.