in a fierce, severe, or cruel manner

to pay close attention to; to focus on something with determination and vigor; to grasp firmly

to make a firm decision; to harden one's heart to do something; firm resolve

showing a malicious or vengeful expression or intent

very fierce

cruel and sinister; showing a desire to harm others through ruthless actions or intent

vicious and merciless

exerting all one's strength

to resolve to do something; to toughen up

fierce and vicious

very fierce

all-out effort or a relentless, vigorous spirit

A colloquial expression used to concede defeat or acknowledge someone's ruthlessness or cleverness, often in a begrudging or admiring way.