What does unimpeachable mean?
Unimpeachable describes someone or something so clearly beyond criticism that it commands unreserved trust. The expression most often characterizes a person's character, conduct, or reputation, but it can also modify evidence, testimony, or an argument that cannot sensibly be challenged. In ordinary use, the word carries a strongly positive, formal tone: it suggests not merely an absence of known wrongdoing but a standard of integrity or credibility that admits no serious objection. A witness may be called unimpeachable because the account is consistent and apparently free of bias, while an institution may have an unimpeachable record because its conduct is exceptionally blameless. The adjective is especially useful when praise must sound emphatic and dignified rather than merely complimentary. It should be reserved for praise or assessments of credibility, since its absolute moral force can otherwise sound exaggerated or rhetorical.
adjectiveSo good or credible that it cannot be criticized or doubted; beyond blame or reproach.
- Too good, honest, or credible to be criticized or doubted.
"Her unimpeachable conduct earned the respect of the entire community."
"The witness gave an unimpeachable account of what had happened."
"The charity's unimpeachable reputation strengthened its appeal to donors."
The “un-” turns a word associated with calling someone to account into a promise of integrity so strong that it leaves no room for reproach.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does unimpeachable come from?
Unimpeachable was formed in English during the 18th century by adding the negative prefix un- to impeachable. Impeachable derives from impeach, which entered Middle English through Old French empechier, from Latin impedicare, “to hinder or impede”; impeachment later developed its modern sense of formally calling a public official to account. The prefix un- therefore converts the idea of being subject to challenge into being beyond challenge or reproach.
Related word forms
How unimpeachable is actually used
This is a formal and strongly approving word. It is commonly used of character, conduct, testimony, evidence, and records, and its emphatic implications can make it sound rhetorical when applied too casually.
Easily confused with unimpeachable
Unimpeachable means beyond blame or criticism, whereas impeachable means open to challenge or criticism and can also refer to a public official subject to removal from office.
Unimpeachable usually implies moral integrity or unquestionable credibility, while impeccable more commonly means flawless in quality, appearance, or performance.