replace

Replace is a verb meaning to take the place of something or to substitute another thing for it; it can also refer to the act of removing something and putting a substitute in its place. The noun form replacement denotes either the item or person that takes the place of the original, or the act of replacing itself.

Etymology traces replace to the prefix re- meaning again or back, combined with place, conveying the sense of putting something in a place again or anew.

In everyday life, replacement occurs when an item is worn out or broken and is swapped for a new one. In manufacturing and maintenance, replacement parts are components designed to substitute worn or failed pieces. In medicine, replacement refers to procedures or therapies that substitute a deficient function, such as organ transplantation or hormone replacement therapy. Replacement also appears in linguistics or mathematics to describe the substitution of elements within a structure.

In computing, replace denotes an operation that substitutes occurrences of a substring with another string. Many programming languages provide a replace function or method, often supporting literal replacement or regular expression-based substitution. In databases, SQL offers a REPLACE function to substitute substrings, while text editors and batch-processing tools commonly include search-and-replace features to modify text across a document or dataset.

See also: substitution, replacement, substitute.