1. To achieve a small victory or advantage over an opponent, giving one the encouragement or confidence to pursue total victory. The underdog tasted blood with her victory in the first round, and she's coming out with guns blazing to try to secure a championship title here today.
2. To have a first experience of something thrilling or exciting that prompts one to seek that experience again. Once I tasted blood skydiving, I knew I had to try to do it as often as I possibly could.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
Fig. to experience something exciting, and perhaps dangerous, for the first time. She had tasted blood once, and she knew that the life of a race-car driver was for her. Once you taste blood, you're hooked.
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.
If you taste blood, you have a small victory and this encourages you to think that you can defeat your opponent completely. The real opposition to the Government continues to be its own backbenchers who have now tasted blood for the first time. Note: You can also say that someone gets a taste of blood. That experience changed him, gave him a taste of blood, a taste of real power.
Collins COBUILD Idioms Dictionary, 3rd ed. © HarperCollins Publishers 2012
taste bloodachieve an early success that stimulates further efforts.
Farlex Partner Idioms Dictionary © Farlex 2017
tv. to experience something exciting, and perhaps dangerous, for the first time. Once you taste blood, you’re hooked.
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.