The Greek noun aspis refers to the asp — a venomous snake, likely the Egyptian cobra. Paul quotes Psalm 140:3 in his indictment of humanity's total depravity: 'the poison of asps is under their lips' (Romans 3:13). The image is stark: human speech, corrupted by sin, carries lethal venom.
The serpent used speech to deceive in Eden (Genesis 3), introducing the archetype of deadly words. In Romans 3, Paul draws from Psalms to prove that both Jews and Gentiles are under sin's power — reaching for the aspis to describe corrupted human speech. But Isaiah 11:8 promises that in the Messianic age the child will play near the cobra's den safely. The Gospel transforms venom into blessing, using mouths once full of poison to proclaim peace and salvation.