We don't have synonyms for isotopes yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are isotope, isotones and isotopies.
(n) :
(nuclear physics) Any of two or more forms of an element where the atoms have the same number of protons, but a different number of neutrons within their nuclei. Thus, isotopes have the same atomic number but a different mass number.
(v) :
(topology, transitive) To define or demonstrate an isotopy of (one map with another).
(n) :
(nuclear physics) Any of two or more forms of an element where the atoms have the same number of protons, but a different number of neutrons within their nuclei. Thus, isotopes have the same atomic number but a different mass number.
(v) :
(topology, transitive) To define or demonstrate an isotopy of (one map with another).