Registering or purchasing a domain name that contains a commonly used word is a bad idea. It can lead to litigation or a UDRP, and it would severely limit a person’s ability to use the domain name.
Some of the words that are trademarks are:
The complete list of words may be found here
Some of the words that are trademarks are:
- Realtor
- Olympic(s)
- Yellow Pages (in some countries)
- Botox
- Laundromat
The complete list of words may be found here