IPA: /ˈmɜːrdərəsli/
KK: /ˈmɜrdərəsli/
In a way that suggests a desire to kill or is extremely aggressive and angry.
He glared at her murderously, making her feel very uneasy.
Murderously → It is formed from "murder" (from Old French *murder*, meaning unlawful killing) and the suffix "-ously" (meaning in a manner characterized by). The word "murderously" means in a manner characterized by murder or extreme violence.
Think of the word 'murder' which refers to unlawful killing, and remember that 'murderously' describes acting in a way that is like committing murder.