The English word “blindsided” means that something has taken someone or some group of people by surprise. This word is used in an idiomatic context from an original physical meaning. It usually refers to something negative that happens, although in some cases, someone might be “blindsided” by an event that may ultimately turn out to benefit them; even so, some form of heavy shock is still implied.
It would seem that the original physical definition of “blindsiding” regards vehicular traffic. If a car or other vehicle comes up beside another without the driver seeing, and hits the other vehicle, the victim is said to have been “blindsided.” This comes from the idea that a “blind” driver, one who cannot see what is happening, is hit from the side with heavy impact. Another more obscure basis for the idiom is the sports arena, where a fighter can be said to have “blindsided” another with a quick, unanticipated punch.
“Blindsiding,” as a vehicle or traffic metaphor, exists within a larger category of English idioms that reflect a focus on automobiles as a metaphorical object. For example, English speakers might propose to, “put the brakes on” something if it is not going well. Likewise, some may talk about a need to refuel,” which, in idiomatic use, just means to rest and recover from something, or to recoup energy, materials, or money over time.
As a fairly modern idiom, “blindsided” gets used in a lot of abstract contexts. Some English speakers will use it fairly often to refer to an unanticipated challenge to groups of planners, such as officials. For example, any sort of municipal or corporate board can be said to have been “blindsided” by one of any number of unforeseen budget challenges, legal liabilities, or in general, anything negative. Journalists can also use this term to refer to consumers or families, for the purposes of showing that someone has been “victimized” in the same general way as if they had been physically blindsided in traffic.
One of the most frequent uses of the word “blindside” in modern times refers to financial damages. For example, someone might say that someone else was “blindsided” by an unexpected bill that is inflated and unaffordable. These negative events, sometimes colorfully described as “raids on [someone’s] wallet,” are commonly described with idiomatic language to show outrage, and suggest that they are extreme and usurious in nature.