Merriam-Webster Collegiate Dictionary - transformation

 noun  Date: 15th century  1. an act, process, or instance of transforming or being transformed  2. false hair worn especially by a woman to replace or supplement natural hair  3.  a.  (1) the operation of changing (as by rotation or mapping) one configuration or expression into another in accordance with a mathematical rule; especially a change of variables or coordinates in which a function of new variables or coordinates is substituted for each original variable or coordinate  (2) the formula that effects a ~  b. function 5a  c. an operation that converts (as by insertion, deletion, or permutation) one grammatical string (as a sentence) into another; also a formal statement of such an operation  4. genetic modification of a bacterium by incorporation of free DNA from another bacterial cell; also genetic modification of a cell by the uptake and incorporation of exogenous DNA