nurikabe

English

A nurikabe being solved.

Etymology

From Japanese ぬりかべ (nurikabe, “an invisible wall in Japanese folklore that blocks roads and delays travel on foot”).

Noun

nurikabe (uncountable)

1. (games, puzzles) A Japanese logic puzzle with a rectangular grid of squares, some of them numbered; the solver is challenged to fill in a subset of squares (under certain constraints) such that each numbered square finally indicates the number of unfilled squares contiguous to it.