Idiom - GCSE English Language Definition

Definition

An idiom is a phrase or expression where the meaning cannot be understood from the individual words alone. Instead of being literal, it expresses a figurative idea that people in a language community commonly understand. 

For example, “hit the hay” means “go to sleep,” not actually hitting hay. Idioms make language more vivid and expressive, but they can be tricky for learners because their meanings are not always clear from the words alone.

Explanation

Idioms are expressions that have developed within languages over time to form their own meaning. Just to look at an idiom in isolation, you cannot work out what it means just by looking at the words separately. They are figurative phrases that mean what we have learned they mean, rather than following the literal meaning of the words within them.

A great example would be when saying you feel “under the weather.” This does not mean someone standing outside under the sunshine or the rain, but to feel sick or unwell. 

These sayings form a meaning that is understood within a culture or community, meaning that speakers of the same language can develop different idioms based on where they are from. This means that there are idioms that are common in the UK, but would not be understood by people from America. Whilst all speaking English, Australian, Canadian and American idioms exist separately from each other. 

Many are shared. This is mostly due to when English was introduced to these countries and how, but some have become shared through common media. 

Idioms are found in all languages and are an important part of everyday speech. They make language more colourful and expressive.

Most idioms cannot be translated directly into other languages. This is because they rely on cultural understanding and shared knowledge within a community.

Idioms often use imagery or metaphorical language, but the key point is that their meaning has become fixed and recognised by speakers of the language.

Idioms play an important role in everyday language. They add colour, personality, and richness to speech, allowing people to express complex feelings in simple, memorable ways. For instance, saying “it’s a piece of cake” communicates ease more vividly than simply saying “it’s easy.” However, because idioms are figurative, they can be difficult for non-native speakers to learn. Their meanings often cannot be guessed from the individual words, so they must be learned as whole expressions.

When you encounter an idiom in a text, you need to think about its accepted meaning rather than the literal meaning of the individual words.

Idioms often use imagery or metaphorical language, but the key point is that their meaning has become fixed and recognised by speakers of the language.

Example

There are many examples of idioms in English language. A well-known one is to “hit the nail on the head,” which means to get some exactly right. Whilst we can work backwards and understand why that phrase may make sense, what makes it an idiom is  that it is a fixed expression whose meaning is established by convention, not logic.

With this, you cannot change the words to something equally as logical - for example, strike the nail in the middle - and expect people to understand your meaning. With an idiom, the knowledge of what it means is an accepted part of the language, so people understand it without context or logic. 

If the meaning depends on literal logic alone, it’s not an idiom (e.g., “close the door”). If the meaning is figurative and conventional, even if understandable, it’s an idiom (e.g., “hit the nail on the head”).

When reading An Inspector Calls, you will see the idiom, “slammed the door in her face,” which means to abruptly and unsympathetically reject. 

Idioms are not just part of English language. For example, the French have “avoir le cafard,” which translates as “to have the cockroach,” and means to feel sad. 

Why do writers use idioms?

Writers use idioms to make their language more relatable, engaging and vivid. 

Idioms can express different ideas, situations and feelings more interestingly and colourfully, making the text more memorable. 

It is especially useful in speech, with dialogue needing to sound more authentic. By picking idioms and common phrases that writers know people use and understand, it makes them seem more real and natural. Readers are often more engaged with texts when they recognise familiar phrases. 

Idioms can also be a strong way to establish the time period, social background and/or location of characters. Some idioms have gone out of more common use, some come from different upbringings. It can be a great way to remind a reader that a character is from someone else, dropping in an idiom of British origin for a character within an American setting, for example. 

They can also add a level of humour or playfulness to a text, especially when mixing cultures, as some create strong visual images that stick with a reader. Writers may play with established idioms by changing them slightly or using them in unexpected ways, which often stand out and can make light of how silly idioms can be. 

In poetry, idioms can contribute to rhythm and sound patterns. They often have a musical quality that adds to the poem's overall effect.

Idioms can also reflect cultural values and beliefs. When writers use them, they're drawing on shared cultural knowledge.

Frequently Asked Questions

What's the difference between an idiom and a metaphor?

A metaphor directly compares two things to create meaning, like "her voice is music to my ears." An idiom is a fixed phrase where the meaning has become established over time, like "it's a piece of cake" (meaning it's easy). Metaphors can be created fresh by writers, but idioms are already established expressions that everyone recognises.

How do I know when something is an idiom?

You can spot an idiom when the literal meaning of the words doesn't make sense in the context. If you tried to understand "spill the beans" as actually dropping beans on the floor, it wouldn't fit the situation. Instead, it means to reveal a secret. The meaning has to be learned rather than worked out from the individual words.

Are idioms always phrases?

Most idioms take the form of phrases, such as “under the weather” or “spill the beans.” However, single words can also be used idiomatically when their meaning shifts from the literal, like tight meaning “stingy.” In your GCSE texts, you’ll usually find idioms as short expressions, but recognising idiomatic uses of single words can also help you analyse how writers play with figurative language.

Can idioms be formal or informal?

Most idioms are informal and appear more often in speech than in formal writing. However, some idioms are more neutral and can appear in various types of text. In your GCSE texts, you'll mainly encounter idioms in dialogue or in less formal writing styles. Understanding this can help you analyse the writer's choice of language register.

Why do some idioms seem old-fashioned?

Language changes over time, and so do idioms. Some expressions that were common in the past are less familiar now. Writers might use old-fashioned idioms to create a historical setting or to show that a character is from an older generation. When you spot these in texts, consider why the writer has chosen to use language from a particular time period.

Related glossaries

Dialogue

Imagery

Metaphor

Euphemism 

Figurative Language

Related revision notes

19th Century Novel: Writer’s Methods & Techniques

An Inspector Calls