Approximately this size. Said while using one's fingers, hands, or arms to visibly demonstrate size. ("Yea" is a variant of "yay" and is pronounced the same way.) "I'll have a small glass of wine, only yea big," he said, holding his thumb and index finger about an inch and a half apart. "Fish have to be about yea big for you to keep them," she said, putting her hand up to her sternum. A: "You were only yea big the last time I saw you!" B: "I was 11, Uncle Jerry. There's no way I was only up to your hip."
yea big(ˈje ˈbɪg)
mod. about so big. (Accompanied by a hand gesture.) Oh, it was about yea big.