Definition of cation in English:



  • A positively charged ion, i.e. one that would be attracted to the cathode in electrolysis.

    The opposite of anion

    ‘When two atoms swap electrons to produce a cation and an anion, the two ions are attracted to each other.’
    • ‘The key step in a unimolecular reaction is the formation of the carbon cation, or carbonium ion, by the departure of the leaving group.’
    • ‘The functional groups of iron hydroxides may sequestrate some cations and anions.’
    • ‘It is called a cation if a positive charge exists and an anion if a negative charge exists.’
    • ‘Non-metals accept electrons in forming anions while metals donate electrons to form cations.’



/ˈkadˌīən/ /ˈkædˌaɪən/


Mid 19th century from cata-‘alongside’ or from cathode, + ion.