Crossword Genius

Ancient viper (3)

Ross

I believe the answer is:

asp

(Other definitions for asp that I've seen before include "One secreting poison" , "Pa's Cleopatra's killer" , "Cold-blooded killer" , "Small poisonous snake" , "Snake, killed Cleopatra" .)

I've seen this clue in The Wall Street Journal.
Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.