IPA: /nɪˈɡlɪdʒəntli/
KK: /ˈnɛɡlɪdʒəntli/
In a way that shows a lack of care or attention to something important.
He negligently left the door unlocked, allowing the dog to escape.
Negligently → It is formed from "negligere" (from Latin, meaning to neglect) and the suffix "-ly" (meaning in a manner). The word "negligently" means in a manner that shows neglect or carelessness.
Think of the Latin word for neglect, 'negligere', to remember that doing something 'negligently' means doing it in a careless manner.