however the trademark on the US patent office states the registrant company as being 'dead'
That can mean any of several things and, once again, the domainer fixation on confusing "is there a trademark" with "is the trademark registered" leads to the usual range of wrong and incomplete answers.
I have a dog. Two years ago, I registered my dog with the state for my dog license. Last year, I didn't pay the renewal on the license, and the license expired. Do I still have a dog? Yes, and it will be happy to bite you. The mere fact that my dog's registration lapsed does not mean that I do not have a dog. My dog is still very much alive.
If there is one thing that domainers can be depended upon to get wrong, it is understanding what trademark registration means in the US. And, please note, my comments here apply to the US registration system.
The USPTO does not "grant trademarks". Under US law, you obtain trademark rights by use of the mark in commerce such that it acts as a distinctive identifier of your goods or services in the marketplace. You don't have to "do" any official act in order to have a trademark, if the thing you are using as a mark performs the function of a trademark. So, if I put "Berryhill" on cans of dog food and sell them, and nobody else is selling dog food with that on it, then it is a mark for dog food. If I put "dog food" on cans of dog food and sell them, then it does not function as a trademark, because "dog food" is not distinctive of a brand of dog food.
Now,
if you have a trademark, you can apply to the USPTO to obtain
registration of your trademark. It's the same thing as registering my dog. First I get a dog,
then I can register my dog.
Federal registration of marks provides a lot of advantages. It provides public notice of your mark. In US court proceedings, it provides presumptive evidence that the mark is valid, distinctive, and yours. You can sue without having a registered mark, but you will be required to prove those things. Also, the amount and types of damages you can recover are enhanced if you have a registered mark. Finally, you can apply to register a mark you are planning to use in the future, but it will not be registered until you actually start using it and provide the USPTO with proof of use of the mark.
Okay, so what does this mean. First off, when you search the USPTO, you are not search a "database of trademarks". You are searching the USPTO records including filed applications, pending applications, old applications, registered marks, and expired registrations. The notation "dead" can mean:
1. the application was refused registration and the applicant gave up
2. a renewal fee for maintaining a registration was not paid, because the owner simply forgot, changed lawyers, or something else; or
3. a couple of other things which I don't feel like typing out.
All it means is that the file in question has reached the end of its natural life at the USPTO. It means that the record you are looking at is not a registered mark. It
might mean they are no longer using the mark. It might not. It
might mean they would have a more difficult time establishing their ownership of the mark. It might not. It
might mean the mark was refused registration for some reason - possibly because someone else has a similar registered mark. Some of those questions can be answered by looking at the complete electronic file by clicking the "TSDR" button you see just above the file data when you do a search.
So, if you find a record with the "dead" notation, it could mean any of several things. it is a useful data point, but it is not the end of the analysis.
As frank said you should be having no issues if you register it for a different class
Or that can cause other problems for you. First off, if you aren't using the domain name
as a trademark for goods or services identified by that mark in commerce in the US, you aren't going to register jack with the USPTO. Secondly, many people monitor trademark registration filings in order to oppose applications similar to theirs - even if the goods or service may be different. So, you can, by filing an application in certain circumstances, attract the fight you didn't want in the first place. Third, if we are talking about a domain name which is a dictionary word or descriptive term, and you are monetizing it to exploit its generic/descriptive meaning, then by filing a trademark application in which you are, by doing so, implicitly claiming that it is not a generic or descriptive term, then you are undermining your best defense in the event of a dispute.
Let me be clear on that third point, in case it is not obvious. Let's say you register "dogfood.tld" and monetize it for dog food. Then you apply for trademark registration. Some trademark owner comes out of the woodwork to your surprise and goes after you. Normally, you would defend yourself by pointing out that it is a generic term for dog food, and that's why you are using it for dog food. But if you are, at the same time, claiming to the USPTO that it is a distinctive trademark, then the question is "Are you lying now, or were you lying to the USPTO" because you can't have it both ways.
The USPTO database is a useful starting point for obtaining helpful information. It is not a magic oracle that answers all your questions.