dead set

from The Century Dictionary.

• noun The fixed position of a dog in pointing game.
• noun A determined effort or attempt; a pointed attack: as, to make a dead-set in a game.
• noun Opposition; resolute antagonism; hostility: as, it was a dead-set between them.
• noun A concocted scheme to defraud a person in gaming. Grose, Slang Diet.
• Extremely desirous of, or determined to get or to do, something: generally with on or upon.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun hunting The rigid pose a hunting dog assumes when pointing out game to a hunter.
• noun figuratively By extension, a determined effort.
• adjective unswervingly dedicated; resolutely determined

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• adjective fixed in your purpose