# treacherous

/ˈtɹɛtʃɝəs/ (US) · /tɹˈɛtʃəɹəs/ (UK) · CEFR B2 · Adjective

Source: https://englishreference.com/word/treacherous
Updated: 2026-05-06

## Definition

dangerous because of hidden risks or because you cannot trust someone. You use this to describe slippery roads or people who might betray you.

For teachers: characterised by hidden dangers or hazards; also describes a person who is guilty of deception or betrayal. Often used to describe environmental conditions like ice or currents.

## Examples

- The mountain roads are treacherous during the winter.
- The hikers decided to turn back because the narrow path along the cliff became too treacherous in the rain.
- The protagonist must navigate a treacherous political landscape where today's allies could easily become tomorrow's enemies in the pursuit of power.

## Usage notes

- Commonly used both literally for physical hazards and figuratively for social or political betrayal.

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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.