Suffix -proof in English

The Suffix -proof in English (Meaning & Examples)

Word formation is one of the easiest ways to expand your vocabulary quickly, especially at intermediate and advanced levels. One very productive suffix in English is -proof.

The suffix -proof is used to form adjectives that describe something as resistant to damage, change, or a particular condition. In simple terms, if something is -proof, it is designed to prevent a problem or protect against it.

In this lesson, you’ll learn common adjectives with the suffix -proof, along with clear meanings and natural example sentences.

What does -proof mean?

-proof = resistant to / protected against

• waterproof → protected against water
• fireproof → resistant to fire
• childproof → designed so children cannot damage or misuse it

These adjectives are common in everyday English, advertising, and technical descriptions.

Common Adjectives with -proof

Ageproof

Meaning: resistant to ageing or the effects of time

The cream is marketed as ageproof, helping to reduce visible signs of ageing.

Breakproof

Meaning: resistant to breaking

The new phone case is advertised as breakproof.

Bugproof

Meaning: resistant to insects

The tent is bugproof, so you can sleep comfortably outdoors.

Bulletproof

Meaning: resistant to bullets

The vehicle is fitted with bulletproof glass.

Childproof

Meaning: designed so children cannot open or misuse it

They installed childproof locks on the kitchen cabinets.

Crushproof

Meaning: resistant to pressure or crushing

The suitcase is crushproof and protects fragile items.

Damp-proof

Meaning: resistant to moisture

The basement is damp-proof to prevent mould.

Dustproof

Meaning: protected against dust

This camera is dustproof and suitable for outdoor use.

Fadeproof

Meaning: resistant to losing colour

The curtains are fadeproof and won’t lose colour in sunlight.

Fireproof

Meaning: resistant to fire

Fireproof materials are essential for public buildings.

Foolproof

Meaning: very easy to use; impossible to misuse

The instructions are foolproof, even for beginners.

Heatproof

Meaning: resistant to high temperatures

Always use heatproof gloves when handling hot dishes.

Leakproof

Meaning: resistant to leaking

She packed her lunch in a leakproof container.

Mothproof

Meaning: protected against moths

He stored his suits in mothproof bags.

Petproof

Meaning: resistant to damage caused by pets

The sofa is made from petproof fabric.

Rainproof

Meaning: resistant to rain

She bought a rainproof jacket for the hike.

Rustproof

Meaning: protected against rust

The metal has a rustproof coating.

Scratchproof

Meaning: resistant to scratches

The watch face is scratchproof.

Shatterproof

Meaning: resistant to breaking into pieces

The windows are made of shatterproof glass.

Shockproof

Meaning: resistant to impact or vibration

A shockproof case protects the phone if it’s dropped.

Slipproof

Meaning: designed to prevent slipping

These shoes have slipproof soles.

Soundproof

Meaning: preventing sound from passing through

They installed soundproof walls in the studio.

Tamperproof

Meaning: protected against interference

The bottle has a tamperproof seal.

Tearproof

Meaning: resistant to tearing

The fabric is tearproof and ideal for outdoor clothing.

Waterproof

Meaning: resistant to water

He wore waterproof boots in the rain.

Weatherproof

Meaning: resistant to different weather conditions

The paint is weatherproof and suitable for exterior walls.

Windproof

Meaning: resistant to wind

She wore a windproof jacket on the mountain.

Common Learner Notes

• Most -proof adjectives are descriptive, not absolute
  (waterproof doesn’t always mean 100% waterproof).
• Many are used in marketing and product descriptions.
• They are usually placed before a noun:
• a waterproof jacket
  childproof packaging

Exam & Vocabulary Tip (B2–C1)

Using -proof adjectives shows strong word-formation awareness, precise vocabulary choice and good control of descriptive language.

They are particularly useful in:

• essays and reports
• product descriptions
• Use of English word-formation tasks

Final Thought

The suffix -proof is a powerful vocabulary tool. Learn a few core examples, understand the pattern, and you’ll be able to recognise and use dozens more with confidence.

Learn about suffix -worthy here

Learn negative prefixes and suffixes in English here

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