The rare daily word game sweeping the globe. Find what's hidden in plain sight.
STACK
Definition of STACK
noun
A pile. A large pile of hay, grain, straw, or the like, larger at the bottom than the top, sometimes covered with thatch. A pile of similar objects, each directly on top of the last.
Wiktionary · CC BY-SA
Where it comes from
From Middle English stack, stacke, stakke, stak, from Old Norse stakkr (“a barn; haystack; heap; pile”), from Proto-Germanic *stakkaz (“a barn; rick; haystack”). The data structure sense is a calque of Dutch stapel, introduced by Edsger W. Dijkstra. Cognate with Icelandic stakkur (“stack”), Swedish stack (“stack”), Danish stak (“stack”), Norwegian stakk (“stack”). Related to stake and sauna.
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.
STACK in OUTLIER
Players have found it on 6 boards so far. 12 players have found it across Outlier's history.
It first turned up on Day 40, 29 June 2026. The most recent board was Day 101, 29 August 2026. Nobody has seen it on a board for 8 days.
First found by a player on Day 40, 29 June 2026.
Built from these letters
STACK starts with S and ends with K. Sorted, its letters read ACKST - 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 STACK
Its neighbours in the OUTLIER dictionary - shortest first.
Also seen on Day 40
Could you have found STACK?
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 40 - and most players walked straight past it.
Play today's OUTLIER