Sudoku meaning / word origin

Sudoku meaning:
digits must remain single.

Sudoku is a logic-placement puzzle played on a 9×9 grid. Its name is a shortened Japanese expression commonly rendered as “the digits must remain single,” which neatly describes the rule that each digit appears once in every row, column, and box.

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数独9MEANING · ORIGIN · LOGIC

Definition

What does Sudoku mean?

Sudoku is a logic puzzle, not a mathematics test. In its familiar 9×9 form, the player places digits 1 through 9 so that no digit repeats in a row, column, or 3×3 box. The important question is never “what do these numbers add up to?” It is “where can this symbol legally go?”

The word Sudoku is a short form of the Japanese phrase sūji wa dokushin ni kagiru, commonly translated as “the digits must remain single.” The name matches the underlying constraint: a digit appears only once in each required unit.

A short Sudoku history

The modern name is Japanese.
The puzzle family is older.

This is a compact orientation, not a claim that one culture invented every grid-based logic puzzle.

1979
Number Place appears in a U.S. puzzle magazine.
The familiar modern 9×9 format was published under the name Number Place before its Japanese name became global.
1984
Nikoli introduces the puzzle to Japan.
The Japanese puzzle publisher presented it under the longer phrase that was shortened to Sudoku.
Today
Sudoku names one clear logical contract.
Players may encounter Number Place or Sudoku; the classic 9×9 rule remains the same: one occurrence of each digit in every row, column, and box.

Continue the definition

Meaning becomes useful
when you read the grid.

See the three rules in action, follow a no-guess walkthrough, or open the free fixed board for a short practice session.

Sources for the name and puzzle context.

For the Japanese publishing context and the “Number Place” naming distinction, see Nikoli’s Sudoku introduction. This page uses those facts to explain the word, not to claim ownership of the wider puzzle tradition.