perfidious
adjective | /perfidious/
tending to betray; deceitful and untrustworthy
perfidious
adjective | /perfidious/
Advanced WordsHARDtending to betray; deceitful and untrustworthy
Learning Progress
Synonyms
Antonyms
Examples
"The spy's perfidious actions were exposed by leaked documents."
"He felt betrayed by a perfidious friend who revealed secrets."
Mnemonic Trick
PERFIDIOUS → PER (through) + FID (faith) — breaking faith, treacherous.
Etymology
From Latin perfidia “treachery.”
Used for betrayal or deceit of trust.
Continue Learning
Community Stats
Track Your Progress
Sign up to save your favorite words and track your learning progress across all vocabulary types.
Take your English vocabulary to the next level
Vocabulary Builder is a smart and comprehensive English vocabulary app designed to help you learn, remember, and master words effectively. Whether you are preparing for competitive exams or improving everyday English, the app goes beyond simple definitions to ensure deep understanding and long-term retention.
