The rare daily word game sweeping the globe. Find what's hidden in plain sight.
SERUM
Definition of SERUM
noun
Ellipsis of blood serum.
Wiktionary · CC BY-SA
Where it comes from
From Latin serum (“whey”). Cognates include French sérum, Spanish suero, Italian siere, siero, Portuguese soro. Doublet of suero.
Etymology via Wiktionary (CC BY-SA).
OUTLIER scores every word on how unusual it is, and that number is not published. Working it out at the board is the game.
SERUM in OUTLIER
Players have found it on 17 boards so far. 22 players have found it across Outlier's history.
It first turned up on Day 21, 10 June 2026. The most recent board was Day 102, 30 August 2026. It was on the latest finished board.
First ever to find it
on Day 21, 10 June 2026 - before anyone else in Outlier's history. See the Pioneers
Built from these letters
SERUM starts with S and ends with M. Sorted, its letters read EMRSU - the shape to hunt for when the grid is scrambled. No letter is used twice, which makes it an isogram.
Same letters, different word
3 other words use exactly these letters. Worth knowing at the board: an anagram fits a grid the same way.
Words that start SERUM
Its neighbours in the OUTLIER dictionary - shortest first.
Also seen on Day 21
Could you have found SERUM?
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 21 - and most players walked straight past it.
Play today's OUTLIER