ISEE/SSAT Vocabulary BuilderWordsPperfidious
ISEE/SSAThard
perfidious
Meaning: treacherous or deliberately faithless
perfidious in a sentence
How perfidious is used in real sentences:
The perfidious ally secretly sold information to the enemy.
The general's perfidious bargain betrayed the soldiers who trusted him.
“His defense claimed the payments were charitable, but a perfidious secretary admitted that he had sworn loyalty to Soria while secretly delivering messages to foreign agents.”
— from the passage The Cipher at Court
“The contractor had been perfidious, promising to protect the fishing grounds while secretly dumping spoil across them.”
— from the passage The Altered Shore
Synonyms for perfidious
Other words for perfidious — treacherous, disloyal and faithless — carry the same meaning.
- treacherous
- disloyal
- faithless
Antonyms of perfidious
Words that mean the opposite of perfidious:
- loyal
- faithful
- trustworthy
Where it comes from
From Latin perfidus, meaning 'faithless.'
Word parts
- fid — faith, trust
perfidious: per- (thoroughly, here 'false to') + fid (trust) + -ious (full of)
Memory hook
PERFIDIOUS contains FID, related to faith: a perfidious person breaks faith.
Practice perfidious in the app