Stab in the back is an idiom that came into use around the turn of the twentieth century. We will examine the meaning of the expression stab in the back, where it came from and some examples of its use in sentences.
A stab in the back is a betrayal, an act of treachery, a demonstration of deceit in the face of trust, disloyalty. A stab in the back is a noun, but there are many other forms for this idiom. Back-stabbing is a noun that means the process of performing treachery or betrayal. The verb phrase stab someone in the back means to betray someone or to be disloyal. Related phrases are stabs someone in the back, stabbed someone in the back, stabbing someone in the back. The idea behind the idiom a stab in the back is that the perpetrator is too much of a coward or too weak to confront his victim, and instead waits until his victim’s back is turned to injure him. The first use of the phrase stab in the back is sometimes attributed to George Bernard Shaw, in an article published in 1916. However, others cite examples of this phrase going back to the 1880s.
Examples
I would be upset if he stabbed me in the back, just based on first impressions. (The Hollywood Reporter)
U.S. Navy Master-at-Arms Matthew McCarty, based at a Naval station in South Carolina and in the service since 2013, said Trump’s ban came as a stab in the back. (Reuters)
The classic hard-right trope is the “stab in the back” myth, of a great national project – normally going to war – betrayed by internal subversion and a lack of fight. (The Guardian)