Of course, the two words, "duck" and "duct," sound similar when spoken. The word "duck" is easier to say when referring to duct tape. Each word has its own definition. I venture that most people couldn't care less about these distinctions.
And lots of that tape is sold as "Duck Tape." Surprisingly, it has nothing to do with taping ducts. And "duck" is a more appropriate name for it.
"Cotton Duck (from Dutch doek,"linen canvas"), also simply duck, sometimes duck cloth or duck canvas — commonly called "canvas" outside the textile industry — is a heavy, plain-woven cotton fabric."
I like the Gorilla version of the product - strong and sticky.