Pronunciation: (kok'shoor', -shûr'), [key]
1. perfectly sure or certain; completely confident in one's own mind: She was cocksure that she was able to do the job better than anyone else.
2. too certain; overconfident: He was so cocksure he would win the election that he didn't even bother to campaign.
3. Obs.perfectly secure or safe.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.