English Reference
Idiom idiom

persona non grata

C1 Formal Roman origin
Meaning

Someone who is no longer welcome, and has been told so.

Examples
SIMPLE

“After the argument he was persona non grata at family dinners.”

CONTEXTUAL

“Two embassy staff were declared persona non grata and given seventy-two hours to leave.”

COMPLEX

“Nobody sent a letter or made an announcement; he simply stopped being invited, which is how persona non grata usually works outside the diplomatic service.”

Origin

Persona began as a theatrical mask, and Roman law turned it into a term of art for the role a person occupies before the law — the sense that survives in English personal, personnel and personality. Grata means pleasing or acceptable. A persona non grata is a person in an official capacity who is not acceptable.

The phrase is diplomatic rather than classical, and it has a precise modern home. Article 9 of the Vienna Convention on Diplomatic Relations of 1961 allows a state to declare any member of a foreign mission persona non grata at any time, with no reason given, after which the sending state must recall them. It is the standard instrument for expelling diplomats, and the wording is deliberately bloodless.

English has taken it well outside diplomacy, for anyone who has been quietly or noisily excluded — from an industry, a family gathering, or a bar.

The Law's Latinconnected storiesSee all Roman origin →

Roman legal Latin that never left the courtroom — or the boardroom.

  1. 01

    bona fide (idiom)

    Genuine and honestly meant — the real thing, not a pretence.

    The Roman standard of good faith.
  2. 02

    caveat emptor (idiom)

    Let the buyer beware — checking what you are buying is your own problem.

    What Rome did not actually say.
  3. 03

    quid pro quo (idiom)

    Something given in return for something else, usually as an understood trade.

    From the apothecary's substitute.
  4. 04

    de facto (idiom)

    In practice, whatever the official position says.

    The question of fact.
  5. 05

    de jure (idiom)

    According to the law, whether or not that is what actually happens.

    The question of law.
  6. 06

    ipso facto (idiom)

    By that very fact — the consequence follows automatically, with no further step.

    Consequences that need no hearing.

Last updated August 3, 2026