# hazardous

/ˈhæzɝdəs/ (US) · /hˈæzədəs/ (UK)

Source: https://englishreference.com/word/hazardous
Updated: 2026-06-20

## Senses

### 1. dangerous

adjective · CEFR B2

dangerous and likely to cause harm or an accident.

For teachers: involving great risk or danger, particularly in relation to physical safety or environmental health.

- The stairs were hazardous because they were covered in a thin layer of ice.
- The factory was forced to close temporarily after inspectors discovered that hazardous chemicals were being stored in leaking containers near the river.

### 2. involving chance

adjective · CEFR C2 · Archaic · Literary

depending on luck or chance rather than a plan.

For teachers: dependent on chance or fortune; unpredictable in nature.

- The traveler took a hazardous path through the woods, hoping for good luck.
- In the poet's view, life was a hazardous journey where one's fate rested entirely on the whims of fortune.

Usage: In modern English, this sense is almost entirely replaced by 'risky' or 'uncertain'.

## Examples

- The waste from the factory is hazardous.
- Heavy snow and thick ice made the mountain roads hazardous for all drivers this morning.
- The disposal of hazardous materials requires strict adherence to safety protocols to prevent long-term environmental contamination and immediate health risks to the local population.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.