The real issue is that due diligence on the word was not done. The copyright this is a load of hogwash, in my opinion looks for words that you need to define in another dictionary is acceptable practice (however, copying the definition verbatim is not).
It's almost like saying "you have a thread scheduler in your operating system and are violating copyright." No, that is a core component of an operating system, just like a word is a core component of the English language (fictitious or not, once it enters an accepted dictionary it becomes a word - other dictionaries are forced to define it due to the nature of language).
The idea was not to claim copyright on the definition, but use the inclusion of the definition in another work as an indication that this other work is a copy of the original work in its entirety.
It's almost like saying "you have a thread scheduler in your operating system and are violating copyright." No, that is a core component of an operating system, just like a word is a core component of the English language (fictitious or not, once it enters an accepted dictionary it becomes a word - other dictionaries are forced to define it due to the nature of language).