The rare daily word game sweeping the globe. Find what's hidden in plain sight.
CASTOREUM
Definition of CASTOREUM
noun
The bitter exudate of the castor sacs of mature beavers, used as a scent mark, and as a tincture in some perfumes.
Wiktionary · CC BY-SA
Where it comes from
From Latin castoreum, from Ancient Greek καστόριον (kastórion).
Etymology via Wiktionary (CC BY-SA).
Word DNA
Line of descent
- Ancient Greek
- Latin
- English
2 recorded generations before English.
Deepest traced root
2nd
of 58 source languages in OUTLIER
12.6%
of traced words share this origin (3,660)
branch · 12.6% of traced words
How it is built
Same root, CASTOREUM · 1 relative in the game
OUTLIER scores every word on how unusual it is, and that number is not published. Working it out at the board is the game.
CASTOREUM in OUTLIER
Players have found it on 12 boards so far. 13 players have found it across Outlier's history.
It first turned up on Day 34, 23 June 2026. The most recent board was Day 145, 12 October 2026. It was on the latest finished board.
First ever to find it
on Day 34, 23 June 2026 - before anyone else in Outlier's history. See the Pioneers
Built from these letters
CASTOREUM starts with C and ends with M. Sorted, its letters read ACEMORSTU - the shape to hunt for when the grid is scrambled. No letter is used twice, which makes it an isogram.
Same letters, different word
One other word uses exactly these letters. Worth knowing at the board: an anagram fits a grid the same way.
Words that start CASTOR
Its neighbours in the OUTLIER dictionary - shortest first.
Also seen on Day 34
Could you have found CASTOREUM?
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 34 - and most players walked straight past it.
Play today's OUTLIER