Any form of an element that has a distinctly different molecular structure to another form of the same element, with different physical properties and often different chemical properties. (defdate)
An other form, a different shape of a lexical unit.
An alternative shape of a cognitive structure.
allotrope
L’ozone est un allotrope de l’oxygène — ''Ozone is an allotrope of oxygen.''
allotropic
(de-adj form of)