first-degree murder

名词noun

1. 1(law, chiefly US, Canada) The criminal offence of murder in a form considered by law to be the most serious; the precise distinction may vary by jurisdiction but typically involves premeditation, or the choice of victim or other circumstances being regarded as especially blameworthy.
2. 2(law, chiefly US, Canada) An act that constitutes the crime of first-degree murder.