A ‘shape’, ‘configuration’, or ‘structure’ which as an object of perception forms a specific whole or unity incapable of expression simply in terms of its parts (e.g. a melody in distinction from the notes that make it up);
I do see that the dictionary defines gestalt precisely how arnie has stated the definition. Here is another definition I found, and this is more the way I've seen it used: "A configuration or pattern of elements so unified as a whole that it cannot be described merely as a sum of its parts." In this one, it can't be described merely as the sum of the parts, but it doesn't say the part is more than the sum of its parts. One way that I've seen it used is if a patient is getting a lot of pills. When you look at them altogether, as gestalt, you can immediately see that they are right. Of course, for patient safety, we have to look at them individually too.