science

Mum's the word

Mum's the word is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Mum's the word rather than just read about it. In short: Mum's the word is a popular English idiom. It is related to an expression used by William Shakespeare, in Henry VI, Part 2.

Key takeaways

Mum's the word belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Mum's the word to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Mum's the word from memory before moving on to harder problems.

Reference excerpt

Mum's the word is a popular English idiom. It is related to an expression used by William Shakespeare, in Henry VI, Part 2. The word "mum" is an alteration of momme, which was used between 1350 and 1400 in Middle English with very close to the same meaning, "be silent; do not reveal".

Meaning "Mum's the word" means to keep silent or quiet. Mum is a Middle English word meaning 'silent', and may be derived from the mummer who acts without speaking. Note the similar English word "mime" (Old English "mīma", Latin "mimus") meaning silent actor or imitator.

Origin The origins of the phrase can be traced back to the fourteenth century and William Langland's narrative poem, Piers Plowman:Thou mightest beter meten the myst on Malverne hullesThen geten a mom of heore mouth til moneye weore schewed! It can also be seen in popular fifteenth-century Towneley Plays:Though thi lyppis be stokyn, yit myght thou say 'mum'. The phrase notably appears in Shakespeare's Henry VI, Part 2, Act 1, Scene 2:Seal up your lips and give no words but mum.

Usages During World War II, variants of the idiom appeared on posters through the United Kingdom reminding citizens to avoid speaking about potential war secrets. Catchphrases included "Be like Dad: Keep Mum" and "Keep mum, she's not so dumb".

Worked examples

Example 1 — a first encounter with Mum's the word

Start with the simplest possible case. Write down what Mum's the word claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Mum's the word before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Mum's the word ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Mum's the word

In research: Mum's the word appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Mum's the word in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Mum's the word is common in secondary-school and first-year university syllabi. It links to neighbouring topics English-language idioms, English language stubs, Vocabulary and usage stubs, so understanding it makes those chapters shorter.
In everyday life: Look for Mum's the word outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Mum's the word in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Mum's the word means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Mum's the word out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Mum's the word in simple terms?

Mum's the word is a popular English idiom. It is related to an expression used by William Shakespeare, in Henry VI, Part 2.

Why does Mum's the word matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Mum's the word?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Mum's the word.