Noun
In the Harry Potter series, an object in which a wizard has concealed a part of their soul through magic, rendering them immortal until the object is irreparably damaged or destroyed.
Synonym: phylactery (general fantasy)
(by extension) Something in which one has invested a part of one's self; an object which allows for the preservation of memory, culture, etc.
Horcrux (plural Horcruxes)
Alternative letter-case form of horcrux.
He is the one, in fact, who realizes that the Basilisk fang is a potential weapon against a Horcrux, and finishes the job right as everyone else is about to be consumed by the ravaging Fiendfyre. Source: Internet
By the end of the book, Dumbledore and Harry set out to the cave where Dumbledore believes a Horcrux resides. Source: Internet
The progress from one horcrux to another is still entertaining, particularly Harry's self-sacrifice to Voldemort in the woods. Source: Internet
The Muggle world is buzzing over the biggest since we all found out that Harry was a horcrux. Source: Internet
She, Harry, and Ron join Dumbledore's Army in the Battle of Hogwarts, during which Hermione destroys Hufflepuff's cup in the Chamber of Secrets with a basilisk fang, eliminating another Horcrux. Source: Internet
They find a basilisk fang to use to destroy the Horcrux made from Helga Hufflepuff's cup. Source: Internet