The rare daily word game sweeping the globe. Find what's hidden in plain sight.
PROLINE
Definition of PROLINE
noun
A nonessential amino acid C5H9NO2 found in most animal proteins, especially collagen; its cyclic structure leads to kinks in the peptide chain of proteins.
Wiktionary · CC BY-SA
Where it comes from
Short for pyrrolidine.
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.
PROLINE in OUTLIER
Players have found it on 13 boards so far.
It first turned up on Day 10, 30 May 2026. The most recent board was Day 118, 15 September 2026. Nobody has seen it on a board for 1 day.
First ever to find it
on Day 52, 11 July 2026 - before anyone else in Outlier's history. See the Pioneers
Built from these letters
PROLINE starts with P and ends with E. Sorted, its letters read EILNOPR - 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.
Also seen on Day 10
Could you have found PROLINE?
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 10 - and most players walked straight past it.
Play today's OUTLIER