Yes. XI is a valid word.
XI is valid in the North American word list used for the Scrabble board game and other crossword tile games.
XI is in the NASPA Word List 2023 (NWL2023), the North American list that Tileside uses for challenges and the one used in club and tournament play.
About XI
XI is said “ksee” in Greek or “zai” in English, and its plural is XIS. With the X on a bonus square where it makes two words, XI can score more than many long words. The Greek letters make a handy set for players: MU, NU, PI and XI are all two letters long. In math and science, the letter xi names variables and particles. Physicists also use it for certain subatomic particles.
Settle the next one at the table: score your game free in Tileside →
XI scores 9 points
Before any bonus squares: X 8 + I 1 = 9. On a double-word square that's 18, on a triple-word 27, and every letter bonus under one of these tiles is applied first.
Example: XI as the first play
Later in the game, put the X on a 3L square and XI is worth 25 before any word bonus.
Hooks: one tile makes a new word
After XI (1):
- XISform of XI: a Greek letter
Place that one tile so it also forms a word in the other direction and both words score.
Longer words from XI
Other forms of XI (1):
- XISform of XI: a Greek letter
Words that start with XI:
Change one tile
Swap any one letter of XI and these are still words:
Same letters, other words
No other word in the list uses exactly the letters X and I.
Memory tip
XI is the Greek letter X, said “ksee” or “zai”. With XU, AX, EX and OX, it is one of the five two-letter homes for the 8-point X.
On these lists
Other two-letter words starting with X
Check words at the table, free
Tileside keeps score, checks words like this one during a challenge, tracks the tiles left in the bag and times turns. It runs in your phone's browser with no account and works offline.
Tileside checks words against the North American list, the NASPA Word List 2023. Your group's chosen dictionary always wins. Playing the international (Collins) list? Turn on its 20 extra two-letter words in Setup.
Word list: NASPA Word List 2023, used under license. NASPA Word List 2023 Edition © NASPA 2023. The copy included in this app is licensed for personal use. You may not use it for any commercial purposes.
Works with the Scrabble board game, played at the table. Tileside is an independent product, not affiliated with or endorsed by the makers of Scrabble.