The rare daily word game sweeping the globe. Find what's hidden in plain sight.

PROOF

/pɹuːf/5 letters

Definition of PROOF

noun

An effort, process, or operation designed to establish or discover a fact or truth; an act of testing; a test; a trial.

Wiktionary · CC BY-SA

Where it comes from

From Middle English proof, from Old French prove, from Late Latin proba (“a proof”), from Latin probō (“to prove”); see prove; compare also the doublet probe.

Etymology via Wiktionary (CC BY-SA).

Rarity score
Withheld
Revealed only in play
Tier
Withheld
Find it yourself

OUTLIER scores every word on how unusual it is, and that number is not published. Working it out at the board is the game.

PROOF in OUTLIER

Players have found it on 14 boards so far. 16 players have found it across Outlier's history.

Day 1Day 120
Its 14 boards, across 120 finished boards · taller bars are busier boards
14
Boards found on
22
First board
114
Latest board
31
Longest gap, days

It first turned up on Day 22, 11 June 2026. The most recent board was Day 114, 11 September 2026. Nobody has seen it on a board for 6 days.

First ever to find it

elishasbooks

on Day 22, 11 June 2026 - before anyone else in Outlier's history. See the Pioneers

Built from these letters

PROOF
5
Letters
2
Vowels
3
Consonants
4
Different letters
2
Longest consonant run
2
Longest vowel run

PROOF starts with P and ends with F. Sorted, its letters read FOOPR - the shape to hunt for when the grid is scrambled. O appears more than once, including a double letter.

Words that start PROOF

Its neighbours in the OUTLIER dictionary - shortest first.

PROOFSPROOFEDPROOFERPROOFERSPROOFINGPROOFINGSPROOFLESSPROOFREADPROOFROOMPROOFREADSPROOFROOMSPROOFREADER

Could you have found PROOF?

OUTLIER is a daily word game. One grid, the same grid for everybody, and the words nobody else spots are the ones that pay. This word was on Day 22 - and most players walked straight past it.

Play today's OUTLIER

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The OUTLIER card for PROOFDownload image