* A misspelling: Perhaps you meant "phacops," which is a genus of extinct trilobites.
* A technical term: It could be a term used in a specific field, like science or engineering. If you can provide more context, I might be able to help you understand its meaning.
* A made-up word: It's possible that "phacups" is a made-up word, perhaps created for a specific purpose.
Please provide more information about where you encountered this word, so I can help you determine its meaning.