cross

Cross is a term with multiple related meanings across disciplines and everyday language. In geometry and design, a cross typically refers to a figure formed by two or more bars that intersect, usually at right angles. The most familiar form is a vertical bar crossed by a shorter horizontal bar, but many variations exist.

As a symbol, the cross carries broad significance. The Christian cross is the central symbol of Christianity, representing the crucifixion and, for many believers, resurrection. Variants include the Latin cross, Greek cross, and heraldic forms such as the Maltese cross or the cross pattée, each with distinct historical and cultural associations.

Cross also appears in infrastructure and daily life. A crosswalk marks a designated place for pedestrians to cross a road, while a crossroads denotes an intersection of two or more roads. The verb to cross means to move from one side to the other or to traverse an area, such as crossing a street or crossing a border.

In science and mathematics, the term is used in specific technical senses. The cross product is a binary operation on two vectors in three-dimensional space that yields a vector perpendicular to both inputs, with magnitude related to the sine of the angle between them. In genetics, crossing (or crossbreeding) refers to mating individuals from different strains or species to produce hybrids.

Other uses include cross-cultural or cross-linguistic contexts, describing interactions across cultures or languages, and cross-references in documents that direct readers to related material. The word derives from Latin cruc-, crux, via Old English crūc, reflecting its long historical usage.