Betrayal

to gain advantage at the cost of someone else's suffering or loss

She threw her colleague under the bus by blaming him for the project's failure when it was a team effort.

to be disloyal and ungrateful to someone who has trusted or supported one

I thought we were close friends, but he stabbed me in the back by spreading rumors about me.

a person who has a tendency to deceive or mislead others and is very likely to betray their trust

He seemed like a trustworthy friend, but he turned out to be a snake in the grass, betraying our confidence.

to be unfaithful or disloyal to someone so as to gain profit oneself

I can't believe my business partner sold me down the river by stealing company funds and disappearing.

to defeat or outperform someone or something with ease

The popular new social media platform left its rivals in the dust, attracting millions of users and revolutionizing the way people connect and share information online.

an act that seems kind but with the intention of betraying someone

She gave him a Judas kiss, pretending to support his project while secretly working against it.

to make no effort to save or defend someone, particularly when they are being severely criticized or being treated unfairly

When the scandal broke, the company's CEO threw the lower-level employees to the wolves to protect his own reputation.

to secretely gather information about a person or group in order to expose them to a person of higher authority, often for one's personal gain

Fearing retribution, the whistleblower decided to drop a dime on the corrupt officials to expose their illegal activities.

to take from one source or person in order to fulfill an obligation or debt to another source or person, often resulting in a cycle of borrowing or rearranging debts without actually resolving the underlying financial issue

Robbing Peter and paying Paul never works, but I guess you have to learn it the hard way.