ISEE/SSAT Vocabulary Builder›Words›P›perfidious
ISEE/SSAThard
perfidious
treacherous or deliberately faithless
Synonyms
- treacherous
- disloyal
- faithless
Antonyms
- loyal
- faithful
- trustworthy
perfidious in a sentence
The perfidious ally secretly sold information to the enemy.
The general's perfidious bargain betrayed the soldiers who trusted him.
Where it comes from
From Latin perfidus, meaning 'faithless.'
Memory hook
PERFIDIOUS contains FID, related to faith: a perfidious person breaks faith.
Word parts
- fid — faith, trust
perfidious: per- (thoroughly, here 'false to') + fid (trust) + -ious (full of)
Read it in context
- The Cipher at Court History
- The Altered Shore Narrative
Practice perfidious in the app