What is the Blood Oath in Harry Potter?

Answer 1

a blood traitor is a pureblood wizard that marries a non-pureblood wizard

Answer 2

a blood traiter is a wizard of pure blood (no muggle parents) who likes muggles and talks to them and stuff....for example Ron and family. a mud blood is a muggle like Hermione

Answer 3

There is no offical blood oath in Harry Potter, however a fan wiki features an article which describes the blood oath as following (please not this is NOT canon information):

It is similar to an unbreakable vow and can only be broken by death. The participants cut themselves to produce a wound that releases blood. They then press the wounds together (usually they palms are cut) until the mood is mingled.

Answer 4

Purebloods that associate with Muggles. Example: The Weasley family.

Answer 5

Harry Potter is a half-blood. His father was pure-blood and his mother was muggle-born.