Get one’s back up is an idiom that has been in use for some time. An idiom is a commonly used word, group of words, or phrase that has a figurative meaning that is not easily deduced from its literal definition. Often using descriptive imagery or metaphors, common idioms are words and phrases used in the English language in order to convey a concise idea, and are often spoken or are considered informal or conversational. English idioms can illustrate emotion more quickly than a phrase that has a literal meaning, even when the etymology or origin of the idiomatic expression is lost. An idiom is a metaphorical figure of speech, and it is understood that it is not a use of literal language. Figures of speech like an often-used metaphor have definitions and connotations that go beyond the literal meaning of the words. Mastery of the turn of phrase of an idiom, which may use slang words or other parts of speech common in American slang or British slang, is essential for the English learner. Many English as a Second Language students do not understand idiomatic expressions and idiomatic language such as hit the sack, spill the beans, let the cat out of the bag, silver lining, back to the drawing board, barking up the wrong tree, kick the bucket, hit the nail on the head, face the music, under the weather, piece of cake, when pigs fly, and raining cats and dogs, because they attempt to translate them word for word, which yields only the literal meaning. English phrases that are idioms should not be taken literally. In addition to learning vocabulary and grammar, one must understand the phrasing of the figurative language of idiomatic phrases in order to know English like a native speaker; it is helpful to maintain a list of phrases, common expressions, colloquial terms, and popular expressions to memorize that are used figuratively or idiomatically. We will examine the meaning of the common saying get one’s back up, where it came from, and some examples of its idiomatic usage in sentences.
To get one’s back up means to become obstinate or hostile, to become annoyed, and to get ready to fight or argue. The idiom get one’s back up describes getting angry or defensive. Often, the term is used in the negative as an admonition, as in don’t get your back up. The phrase get one’s back up came into use in the 1700s; the image is that of a cat arching its back in an aggressive posture. Related phrases are gets one’s back up, got one’s back up, gotten one’s back up, getting one’s back up.
Resist the urge to get your back up with a “get off my lawn, punk” snarl. (Modesto Bee)
Before you get your back up listen to what they say, not how they’re saying it. (Sydney Morning Herald)
And don’t get your back up when you don’t like something you hear. (La Grande Observer)