How to Write Definitions in Exams So You Don’t Lose Half Marks

2026-01-07 · 9 min

Term, class, distinguishing feature — and why examples are not definitions.

An example is not a definition. Photosynthesis is when plants are in the sun points at the neighbourhood and misses the class and the feature. Write term, class, distinguishing word. Put the sun on the next line if the question asked for an illustration.

Class and feature

A mark-earning definition usually has three parts, even if they sit in one sentence. Name the term again if you need to steady yourself. Place it in a class: a process, a force, a type of word, a compound, a system of government. Then give the feature that separates it from neighbours in that class. Photosynthesis is the process by which green plants make food using light. Process is the class. Make food using light is the feature. Sun is an example hiding in the wings, not the definition.

Examples come after, if the question asked for an example, or if a second mark is clearly for illustration. Mixing them early is how the definition mark disappears and the example mark is not clearly awarded either. Write the definition. Full stop. Then For example, .... The full stop is a kindness to the marker. Kindness to the marker is not softness. It is how half marks become whole.

Precision words often carry the mark: only, aqueous, green, closed, narrator, average, perpendicular. Leaving them out can turn a definition into a neighbour's definition. Diffusion and osmosis are both movement stories. The distinguishing feature is what moves and through what, as your syllabus stated it. If you cannot remember the precision word, do not replace it with a long story. A long story is still an example in a coat.

Precision words often carry the mark: only, aqueous, green, closed, narrator, perpendicular. Leaving them out can turn your sentence into the neighbour’s definition. Diffusion and osmosis are both movement stories. The split is what moves and through what, as your syllabus stated it.

Do not start with is when or is like if you can start with is a. Is when often leads to a scene. Is a leads to a class. Scenes are for composition. Classes are for definitions. Teachers who say define in your own words still want the class and the feature. Own words does not mean own science. It means you did not copy a paragraph you do not understand. Understanding shows up as a short, accurate class.

Learn definitions in pairs that students confuse. Speed and velocity. Mass and weight. Weather and climate. Simile and metaphor. Evaporation and boiling. Write both, then write the one feature that splits them. Pair work is how you stop offering the neighbour's definition under time. Time makes the brain grab the first related scene. Scenes are usually the more famous example, not the class.

Pairs students confuse

Practise from memory, then check the missing word. Cover the page. Write. Uncover. Circle the precision word you dropped. Write that word three times in a sentence of your own. This is dull and it works. Reading the definition ten times feels like study and leaves the same hole. The hole is why half marks remain on the scheme for the feature you almost said.

If a question says what is meant by, it still wants a definition, not a history of the idea. If it says give an example of, do not define for six lines and forget the example. Read the verb. Define, state what is meant by, what is, and give the meaning of are close family. Illustrate, give an example, and name one instance are a different family. Different families, different sentences.

In calculation papers, definitions still appear. Write them completely before you compute. A correct sum with an empty define line is two marks that would have taken thirty seconds.

In calculations papers, definitions still appear and still lose half marks while students rush to the sum. Write the definition in the space it was asked, completely, before you compute. A correct sum with an empty define line is a visible leak. The leak is often two marks that would have taken thirty seconds. Thirty seconds is cheaper than a long method on a later item you may not finish.

Language papers define literary terms the same way. A metaphor is a comparison that does not use like or as. Class: comparison. Feature: no like or as. Saying a metaphor is when you paint a picture is waffle. Paint a picture might be allowed as extra. Extra without the class rarely buys the first mark. Buy the first mark. Then paint if you have time.

Build a thin booklet of the definitions your mocks actually asked, not a dictionary of the universe. Universe booklets are never revised. Mock-asked definitions are a population that will resemble the next paper more than a random glossary will. Add a pair for each. Add one example underneath in a different ink or a labelled extra line so you never confuse example with definition again.

Start with is a, not is when. If you freeze, write the class first. A class alone may still take a half. An example alone often takes nothing.