What does "by no stretch of the imagination" mean?

What does it mean? I hear the phrase being used a lot and I searched the dictionary but I don't understand it. If anyone can provide an answer, thank you.

• Seems self-explanatory to me, OP. It means "unimaginable", even to the most capable imagination: "no matter how much you might stretch your imagination, you couldn't possibly conceive of this". What's not to understand?

• I typed "by no stretch of the imagination" into the Google search window, and the first several results that came up were explanations of the phrase. If OP didn't have enough smarts to do that, it's no surprise s/he can't understand the expression.. Maybe the alternate version, "not by any stretch of the imagination," would be clearer to OP. But I doubt it. And anyway, it means exactly the same thing.

• Perhaps the OP is the same one who insists that old biddies are really old bitties because some semi-literates made up a fake online dictionary containing their misspelled words, mixed-up metaphors and inarticulate verbal expressions.

• OP, that phrase links to "dumb twat", which links to "time waster" and then directly to your FB page.

• Here you go!

  http://lmgtfy.com/%3Fq%3Dby+no+stretch+of+the+imagination