That word? That word?

Do you ever have a word on the tip of your brain, but you just CAN'T pull it up to the surface? Uggh! That is exactly what is happening to me tonight. I really wanted to learn how to do _____ with my serger. I've seen it done on one of the sewing shows on OETA on Saturday morning. I would love to Google..or YouTube it right now, but I can't pull the word up out of my brain to type it in. So... if you just happen to be passing by, and want to put me out of my misery, can you tell me what they call it when the fabric at the top of a baby's dress is all gathered up, and then sewn on top? Please?