#5 'Avalanche'
WWE tried to trademark the term ‘avalanche’ in 2011, but the circumstances of the trademark application are a bit vague. The general description only mentions ‘entertainment services in the nature of wrestling contests, personal appearances by a wrestler, etc.’, without any additional information.
It’s unusual because, a) the term avalanche is already used in wrestling (for example, the term ‘body avalanche’ to describe a big wrestler falling on another); and b) it’s one of those things that could suffer from unintentional double entendre very easily.
Imagine reading the following headline: “Avalanche kills thirty in French Alps”. That’s likely to cause confusion for people possibly looking for the term ‘avalanche’ in a wrestling-related context. Simply put, it’s one of those unusual trademarks that simply don’t make sense.