taste blood

taste blood (third-person singular simple present tastes blood, present participle tasting blood, simple past and past participle tasted blood)

1. To sense weakness in another, encouraging one to attack or (figurative) to press home an advantage in a debate etc.; (by extension) to take pleasure in something new.
   • 1968 January, Henry S. Resnik, “Passion on a Bicycle”, in The Atlantic‎^[1], →ISSN, archived from the original on 6 December 2022:

     […] in those few moments I had proved myself a cyclist of such enormous cool, such dazzling technique, that I knew I would never again slow down for an advancing truck, veer to avoid a threatening limousine, or hesitate to plunge into the midst of a pedestrian phalanx. I had tasted blood, and now I knew what all those pillar-legged hostelers felt as they sat around their campfires, recalling the encounters and skirmishes of the day.

   • 2012 July 14, Matt Williams, Ewen MacAskill, “Obama repeats attack on Romney as 'pioneer of outsourcing'”, in The Guardian‎^[2], →ISSN, archived from the original on 8 June 2018:

     But having tasted blood on the issue, the Obama campaign kept jabbing away.

• “taste blood”, in Collins English Dictionary.