In simple terms, a "ruthless streak" means having a tendency or quality of being very harsh, cruel, or uncompromising in one's actions or decisions.
Sentences with «ruthless streak»
The useful post aims to help those of us who weren't born with a Steve Jobs - style ruthless streak learn to say no without feeling like complete jerks or damaging relationships and offers specific tactics and phrasing to use, including: (inc.com)
Arsenal have to look beyond the norm and punish everyone that comes in front of us with a real ruthless streak. (justarsenal.com)
The race to succeed Paddy Ashdown - already dubbed the battle of the Seven Dwarfs - is demonstrating that Britain's nice party also has a pretty ruthless streak. (theguardian.com)