perfidiousness

C2+ Topic:Abstract Ideas

US /pərˈfɪdiəsnəs/ UK /pəˈfɪdiəsnəs/ See IPA manual

Meanings

1

noun
the quality of being deceitful and untrustworthy

His perfidiousness cost him every friend he had.

Thesaurus

Synonyms

1 noun · the quality of being... treachery perfidy disloyalty faithlessness betrayal duplicity falseness

Opposites

loyalty fidelity faithfulness trustworthiness

Word family

Related forms perfidious perfidy

Etymology

From perfidious (from Latin perfidus 'faithless') + -ness. Perfidus is from per- ('through, away') + fides ('faith').

perfidus Latin fides Latin

View etymology graph ->

Topics

Abstract Ideas Word Formation & Derivatives

External links

# perfidiousness

**Type:** Word
**Level:** C2+
**Part of speech:** noun
**IPA (US):** /pərˈfɪdiəsnəs/
**IPA (UK):** /pəˈfɪdiəsnəs/

## Meanings
1. the quality of being deceitful and untrustworthy

## Examples
- His perfidiousness cost him every friend he had.

## Synonyms
- treachery
- perfidy
- disloyalty
- faithlessness
- betrayal
- duplicity
- falseness

## Antonyms
- loyalty
- fidelity
- faithfulness
- trustworthiness

## Related Forms
- perfidious
- perfidy

## Roots and Affixes
- Root: perfidus
- Root: fides

## Etymology
From perfidious (from Latin perfidus 'faithless') + -ness. Perfidus is from per- ('through, away') + fides ('faith').

## AI Etymology
Perfidiousness is from perfidious (from Latin perfidus 'faithless') + -ness. Perfidus is from per- ('through, away') + fides ('faith'). Important recorded forms include perfidus (Latin) and fides (Latin). Morphologically, the word preserves a built structure whose named elements carry the historical sense into English. The modern sense remains close to that composition, with the parts narrowing into a single lexical item. In current use it covers the quality of being deceitful and untrustworthy. The wider family includes related words such as perfidious and perfidy.

## Topics
- Abstract Ideas
- Word Formation & Derivatives

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