I'm designing a data structure that disallows inserting the same element twice, and I want to give it a name. Is there a single word for "fear of duplicates?" "Dupliphobia" sounds wrong.
How about antigrafíphobia? From Greek word αντιγραφή • (antigrafí), “act of copying")+phobia.
How about "uniquified"? To uniquify something in the computational sense is to ensure uniqueness of its elements.
The fear of duplication is called Clonophobia.