Crossword puzzles

A crossword is a word game consisting of a grid of black and white squares with numbers on the corners, into which solvers enter words or phrases ("entries") crossing each other horizontally ("across") and vertically ("down") according to a set of clues. Each white square is typically filled with one letter, while the black squares are used to separate entries. The first white square in each entry is typically numbered to correspond to its clue. Crosswords commonly appear in newspapers and magazines. The earliest crosswords that resemble their modern form were popularized by the New York World in the 1910s. Many variants of crosswords are popular around the world, including cryptic crosswords and many language-specific variants. Crossword construction in modern times usually involves the use of software. Constructors choose a theme (except for themeless puzzles), place the theme answers in a grid which is usually rotationally symmetric, fill in the rest of the grid, and then write clues. A person who constructs or solves crosswords is called a "cruciverbalist". The word "cruciverbalist" appears to have been coined in the 1970s from the Latin roots crucis, meaning 'cross', and verbum, meaning 'word'.