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perfidiousness

perfidiousness

9.9
A way of acting that is disloyal and betrays someone's trust
  • noun
  • /pərˈfɪdʒəsnəs/
  • Formal
translation icon : perfidia
  • The perfidiousness of her actions left a lasting impact on their relationship, eroding trust completely.

Examples

  • His perfidiousness was evident when he betrayed his closest friend for personal gain.

  • During the investigation, the detective uncovered the perfidiousness of the suspect's plot against the company.

  • This short historical overview will demonstrate the importance and perfidiousness of Jewry and its animosity toward the founder of Islam, the Prophet Muhammad.

    Academic text (2015)

Synonyms

betrayal
vsperfidiousness
197 3.9

An act of not being loyal to someone, for example telling their secrets or helping an enemy

is the general state of being treacherous rather than one specific act
treachery
vsperfidiousness
46 7.5

To betray someone's trust or loyalty

is the lasting character trait that underlies such betraying acts
disloyalty
vsperfidiousness
13 4.1

Not supporting a person, group, or cause who trusts you

is a stronger sense implying treachery and active betrayal of trust
perfidy
vsperfidiousness
  • Formal
4 9.9

A dishonest act that breaks someone's trust

is the enduring quality or state behind such deceitful acts
unfaithfulness
vsperfidiousness
1 6.1

Not being loyal to a partner, for example having a secret romantic or sexual relationship

is broader, applying to any betrayal of trust beyond personal relationships
faithlessness
vsperfidiousness
1 7.7

Not being loyal or keeping promises to people who trust you

is focused more on deliberate treachery than general unreliability
traitorousness
vsperfidiousness
8.8

Being disloyal to your country, friends, or cause

is the broad quality of betraying trust in any situation
traitorism
vsperfidiousness
9.9

The act of betraying your country or people by helping their enemies

is the general quality of breaking trust rather than acting against a group
unfaith
vsperfidiousness
  • Archaic
9.7

Lack of loyalty that breaks trust between people

is the overall quality or state rather than one isolated act

Antonyms

503 1.3

Strong and lasting support for a person, group, or idea

How Treacherous

treachery
46 7.5
perfidiousness
  • Formal
9.9
deceit
66 4.6
dishonesty
46 3.2

Surface Forms

Morphology

perfidiousness = perfidious (transparent) = perfidious + ness

Standard nominalization formed by adding '-ness' to an adjective, producing 'the state or quality of being perfidious', which is directly predictable from the adjective.

Etymology

Perfidiousness comes from the Latin parts per- and fid, where fid means 'faith' and appears in familiar words like fidelity and 'faithful', while per- gives a sense of 'against' or 'away'. So perfidiousness is the quality of turning against faith—betrayal or being untrustworthy.