English Reference
Idiom idiom

judge a book by its cover


To make judgments about things or people by considering external appearances alone.

Meaning adapted from Wiktionary, available under CC BY-SA 4.0.


SIMPLE

You should not judge a book by its cover.

CONTEXTUAL

The new manager looked quiet and shy, but I learned not to judge a book by its cover when she led the team to success.

COMPLEX

While the dilapidated building appeared abandoned and uninviting, one must never judge a book by its cover, for the interior housed a vibrant and thriving community center.


Related idioms8entries
  1. 01

    bad books

    Disfavor.

  2. 02

    balance the books

    To add up all the debits and credits.

  3. 03

    Barnaby Rudge

    [Cockney slang]judge

  4. 04

    blot one's copy book

    To damage one's own reputation through bad behavior.

  5. 05

    blow someone's cover

    To reveal that someone's behavior, situation, or identity has been fabricated or deliberately misrepresented for an ulterior motive.

  6. 06

    book burning

    Any mass destruction, removal, or recalling of books, motion pictures, broadcasts, or electronic works as a form of censorship, especially motivated by religious or political objections to the material.

  7. 07

    book dumping

    The practice of donating old used books that burden rather than assist communities.

  8. 08

    book in

    To check in (to a hotel).

Last updated August 10, 2026