HI :) First, the original sentence is " 우기는 데는 이길 장사 없다 " from the first part, 우기다 means to insist or to give an opinion strongly regardless of the others ( being stubborn) e.g. situation 1, ( you think your friend ate your food and she keeps saying she didn't "BUT you don't believe it) 친구가 나의 음식을 안 먹었다고 우겼다. ( my friend insisted she didn't eat it ( but i don't trust it in my mind )) (you can just think the behavior "우기다" means being stubborn ) ~하는 덴 = ~하는 데는 means Speaking about someone doing/saying something ( you can also change it to~ 말하자면 " if i say about ~ ) e.g. speaking of her studying hard, there is a reason 그녀가 열심히 공부하는 데는 이유가 있다. 이기다 = to win ~ 하길 = "TO" e.g. 열심히 공부하길 잘했다 지금 말을 잘 할 수 있어! It's been good to study hard, I can now speak well! 장사 means a strong man honestly, you don't really need to know that :) cuz what you have to focus on is what the sentence is meaning So, 우기는 데는 이길 장사 없다 can be translate into " speaking of her or him insisting the opinion / being stubborn, there is no a strong man to win/defeat it " in other words, if i translate it freely, it would be " we can't defeat what she's insisting ( cuz she is stubborn) " it's good to be curious all the time but try to avoid translating Korean language into your language directly/ perfectly i would recommend you to focus on the situation when the sentence is used :) Thank you Ah i forgot to say this... do not trust papago : ) haha

In this case, "덴" is not used by bound noun. "덴" is used short word such like abbreviation. "덴" is means " ~것에 대해서는 = about what someone do/say I would like to translate about full sentence like below. " There is no way to win what he insist one's own opinion " it is badly meaning.