A good name is unique, and stands out but should ideally create a positive association with it, especially your target demographic. When it comes to naming new products, companies will spend sometimes months and go through thousands of options before arriving on the one that they'll ultimately go with. Don't rush this process because its ultimately much more costly to have to go back or change, or ultimately fail because the name did not resonate enough with your target demographic.

The name is not everything but it's a huge part. Go to techcrunch or cruncbase and look at any number of new start ups which are probably all great ideas or products but because they have either a dumb name or a not so unique name, they can fail. My personal pet peeve is the stilted and formulaic neologism of adding "ly" at the end of any noun or verb---perfectly hilariously noted throughout HBO's Silicon Valley. At this point, we are all more clever than this.
Anyway, when you have only seconds to make an impression on a consumer, the last thing you want is cognitive dissonance caused by the name. Cognitive dissonance occurs when the signifier is not what is signified and vice versa; you're looking at a bicycle but someone insists it's a fish. And you're like, wtf.

This happens when you're looking at a great product but then it unexpectedly has a weird or dumb name, a range of slight neorological impressions then occur, effecting the emotional relationship between consumer and product: confusion, annoyance, distrust, etc. All of these slight negative responses are not what you want associated with your product when you only have seconds to make an impression. That's why a good name matters.

Now to your name: Dude Undies. Scrap this immediately. First of all, when it comes to men's underwear (I'm assuming this is your product), this is dangerous minefield territory because whether you like it or not, you're automatically dealing with issues of male insecurities involving self worth, virility, potency, etc

Some light word association exercises (maybe among your friends) might be helpful in yielding an alternative to "undies" which i associate with: children, bedtime, potty training, etc.Absolutely not what men want to be wearing. You can see why this word next to "Dude" is cognitive dissonance in and of itself, never mind your product.

I suggest you go back to the drawing board on this. Think about what makes your product different from your competitors', what value are you bringing to the market? Play with these ideas make a list of at least 50 words (thesaurus.com is very helpful) find a word or words that at least create that same impression. From my own observations, I've found that men love products with as few syllables as possible.

If this is too daunting for you, enlist the help of a good copy writer with experience in product naming (I know a few if you need one), they should be able to give you a list of ad campaigns that they worked on. Paying them $100 for a good name is worth it in the long run.

I hope this helps, best of luck to you!