It's actually "cul de sac", a French expression for "bottom of the bag", and is pronounced well, more like it's spelling would suggest than "coldasack". It's a term used for any "dead-end", including roads.

All of that aside, I've never heard the expression in the context of web development, sorry.

Come on man - dont bust my chops over stupid stuff like that - anyone know what a Cul Da Sac in sites means?

I'm not busting your chops, and it isn't "stupid stuff". I'm educating you so that you can use the term correctly. If you attempt to search for it, you should know the correct spelling, "cul de sac". The individual terms aren't capitalized, and it's often hyphenated as "cul-de-sac".

I already explained I've never heard the term used in the context of web development. I suspect you saw the term being used in its original sense, meaning a "dead end" on the web, and not as a technical term. I can imagine an SEO company using the term to explain that your site is a dead-end and that they can help you get more "traffic". I can also see how the term might apply to a page on your site with no hyperlinks or navigational elements. The user would have to "back-up" out of the page, thus it might be called a cul-de-sac.

Perhaps if you explained what it is you would like to do, you might get more worthwhile answers. As it is, people could only answer "yes" or "no" to your question. I'm assuming you want to do something specific. If you would expand your question a bit, I'm sure you'd get answers that you'd find more valuable.