The Cartoon - S9-E13
Continuity mistake: After George and Janet leave The Apartment, Jerry gets mad at Kramer for saying Janet looked like him. He shoves Kramer and the bottom half of the freezer door swings open. The next few shots show Jerry and Kramer from the chest up, but when a wide view shot is shown again, the freezer door is closed. It does not appear Jerry shut the door.
Answer: The name is Delores. He shouts that name at the end of the episode. Then in a later episode, "The Foundation", he runs into her. And he repeatedly calls her Delores.