What's the difference? Crisp vs. crumble
According to Pam Anderson in "The Perfect Recipe," for a crisp the fruit is topped with a mixture of butter, sugar, flour and nuts; a crumble is the same but has oatmeal added to the topping. A betty is topped with buttered bread crumbs, and usually has layers of crumbs in between fruit layers. Also, in a cobbler the fruit is covered with a biscuit dough and baked until golden brown; same with a grunt, except the dish is covered so the topping steams rather than bakes. A buckle is topped with a cake-type batter and baked. Who knew there could be so many variations?
My understanding is that a crumble's pastry is essentially butter, flour, and sugar, all crumbled up and sprinkled on top, whereas a crisp's topping is more granola-like, and can include stuff like rolled oats, coconut flakes, nuts, etc.
A cobbler is basically fruit baked under a thick pie crust, differing from a pie only in its lack of bottom crust.
re: Tom Meg
I don't think this is accurate. One of my favorite crisp recipes, from a New England cookbook, calls for a topping made from 1 cup flour, 1 cup sugar, 1 egg, and a bit of baking powder. This is mixed together, first with a fork and later with fingers until it is mealy. It is patted over unsweetened fruit, such as apples, to cover the fruit. Then some melted butter is spread over the top. A sprinkle of cinnamon is optional. A 375 degree oven for 40 minutes or so does the trick. It can even be made early in the day and reheated after the main course comes out of the oven.
I suspect that lots of these names are regional names, and really have little to do with the details of how the dessert is constructed.