Expert Answers
parkerlee eNotes educator| Certified Educator

I understood it to mean Harry himself! When as a baby he was struck by Voldemort, some of Voldemort's power went into him ('Highlander' style!) at the same time. This is why the selecting hat at the beginning of the story wanted first to put Harry in the House of Slytherin, and this is also why Harry could understand and speak snake language (which he accidentally discovered upon his visit at the zoo.)

Ever since that fatal day when his parents succumbed to the power of Voldemort, Harry has been "charged" with Voldemort's energy, as if a part of the invincible wizard's strength had muted over to him. (Even his mark is upon him, the zigzag lightning scar on his forehead.) In this sense Harry is a sort of half-blood, sharing the traits of the very Enemy he must confront and defeat. (For those of us old enough to remember, this is reminiscent of the "Star Wars" struggle between Luke Skywalker and "Darth Vader," in verlon meaning 'Father.')

One of the references below is an on-line poll taken before the seventh and final book of the Harry Potter series came out - have a peek!

taangerine | Student

In Harry Potter, Severus Snape is the half blood prince. 

atyourservice | Student

Severus Snape is the Half-Blood Prince.

crystaltu001 | Student

Severous Snape is the Half-Blood Prince. He is a half-blood, half muggle, half wizard. His mother's last name, I believe, is Prince, therefore, he called himself the Half-Blood Prince. 

Wiggin42 | Student

Severus Snape called himself the Half-Blood Prince. We know this because that is the name he wrote in his Potions textbook. Of course, that could also be extended as a metaphor for Harry Potter himself; and to an extent even Voldemort. Funny how they all half blood wizards, no? 

gelsaied | Student

Severus Snape is the half-bllod prince.

His father was a non-wizard (muggle) and his mother was a full blood, hence the name Half-Blood.

brenduucha | Student

Severus Snape is the Half-Blood Prince.

He called himself like that because his father was a muggle. That's why Half-Blood

And he called himself Prince, not because he is a prince with a princess, but because his mother's single last name is Prince.

xxalannahxx | Student

Professor Snape is the Half-Blood Prince. At the start of the book he swears to the Unbreakble Vow in which he swears to protect Draco Malfoy and if he cannot carry out the deed Lord Voldemort propositioned him to do then Snape would have to do it. Harry takes potions but doesn't have books as he thinks that Snape is still teaching however its Slughorn that is teaching potions now so he can and as he doesn't have any materials he uses one of the schools old books which turns out to be Snapes old book and it is written all over in with useful tips for how to make potions better 

trhchris1 | Student

yes but Parkerlee near the end of the book harry gose after Snape and use a spell on Snape he learned from the potions book. after he dose that Snape says "how dare you use my own spell against me.

mh41602 | Student
Professor Snape is the Half-Blood Prince. In the beginning of the movie he is propositioned and swears to protect Drako Malfoy no matter what. If he fails to protect him, Snape swears to carry out what Voldimort has asked Drako to do. Harry Potter is to stop Drako and finds out that Professor Snape is on his side. If you read the story you learn in the first chapter about the curse that is put upon Snape. In the end Drako is too afraid to carry out his quest.