the act or an instance of transforming or being transformed

in mathematics, the operation of changing, e.g. by rotation or mapping, one configuration or expression into another in accordance with a mathematical rule, esp a change of variables or coordinates

in linguistics, any of a set of rules for transforming the supposed underlying structures of a language into actual sentences

in biology, the modification of plant or animal cell culture, e.g. by a cancer-producing virus, resulting in unlimited cell growth and division

in genetics, the modification of a cell, esp by a bacterium, by introduction of DNA from a genetically different source