The rare daily word game sweeping the globe. Find what's hidden in plain sight.
ISOOCTANE
Definition of ISOOCTANE
noun
any isomer of n-octane; especially 2,2,4-trimethylpentane, used as a reference in the determination of the octane number of fuel
Wiktionary · CC BY-SA
Where it comes from
From iso- + octane.
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.
ISOOCTANE in OUTLIER
Players have found it on 4 boards so far.
It first turned up on Day 72, 31 July 2026. The most recent board was Day 110, 7 September 2026. Nobody has seen it on a board for 10 days.
First ever to find it
on Day 74, 2 August 2026 - before anyone else in Outlier's history. See the Pioneers
Built from these letters
ISOOCTANE starts with I and ends with E. Sorted, its letters read ACEINOOST - the shape to hunt for when the grid is scrambled. O appears more than once, including a double letter.
Words that start ISOOCT
Its neighbours in the OUTLIER dictionary - shortest first.
Could you have found ISOOCTANE?
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 72 - and most players walked straight past it.
Play today's OUTLIER