Usually with reference to classical languages: the alteration of a word by addition, removal, or transposition of letters or syllables; an instance of this.
rare The transposition of words from their usual or natural order.
Old English. From post-classical Latin metaplasmus (3rd cent.; recorded in classical Latin authors as a Greek word) from Hellenistic Greek μεταπλασμός from ancient Greek μετα- + -πλασμός (from πλάσσειν to mould, form + -μος, suffix forming nouns), after μεταπλάσσειν to model differently, remould.
Originally: the granular (as opposed to the hyaline) portion of cytoplasm, containing various inclusions. Later also: granular substance within a nucleus, especially that of a plant oocyte or ovum.
Late 19th century; earliest use found in Alfred Bennett (1833–1902), botanist and publisher. From German Metaplasma from meta- + -plasma.