Q. How come there’s no difference between “fat chance” and “slim chance?"

A.     It is what’s technically known as an idiot’s syncrisy of the language. Like, for example,

“slow up” and “slow down”—the same thing. Or “regardless” and “irregardless.” And “I couldn’t care less”—or, nowadays, “I could care less.” See? Still, to get back to the original query, and it certainly is queer, “slim” isn’t always equated with “fat,” as in the following joke:

First girlfriend: “Have you slept with him yet?”

Second girlfriend: “Fat chance!”

Well, who would, if the lover in question is some slobiferous pachyderm with a midriff like a Goodyear blimp and rapine in his bloodshot eye? But, come to think of it, I’ve never heard of some slender youth being turned down with “Slim chance!” either. Girls usually say, “Get lost!” and—I’m sorry, we can’t give advice to the lovelorn, this is a science feature.

The Caribou

Professor:      "I am here on the North Slope recording a bilingual caribou, who speaks a unique Eskimo dialect . . . Will you illustrate, please?"

Caribou:         "drzlyfumnpxksrccbggujalkr”

Professor:      "Meaning?"

Caribou:         “One o’clock”

Professor:      "May we have another example?"

Caribou:         “gxh.”

Professor:      "Translated how?"

Caribou:         “The place where two oceans meet in a bay that goes inland through a purple fjord that turns pale and then not so pale and goes on and on, in and out and then narrows somewhere but floods in May and maybe part of June.”

Professor:      "Any other expression, not so nuanced, that we may be interested in?"

Caribou:         “landscapeintruisionsinthenameofcivilizationalloverthespillspoiledplace

                        bypropernounsexxonandbritishpetroleumforimproperpurposes.”

Professor:      "We can almost decipher that."

Caribou:        " In plainer English: 'Men come now and dig dig and pump pump and lay down big pipe and seep and soak the land with poison, and may they go to blazes without taking us with them.'”

Professor:      "Thank you very much."

Caribou:         "You are not welcome."

            
Moral: Enough said.