modification

The act or process of modifying or the condition of being modified.

A change or a result produced by modifying.

A change undergone by a word that is borrowed from another language.

A phonological change undergone by a word or morpheme when it is used in a construction, as the change of will to 'll in they'll.

In biology, a change which is brought about in a living being by its own activity and is not transmitted to descendants, as contrasted with a variation regarded as a congenital change which is not the effect of the activity of the organism and is transmitted to descendants; an acquired character.