Definition of amphoteric in English:



  • (of a compound, especially a metal oxide or hydroxide) able to react both as a base and as an acid.

    • ‘Amino acids are amphoteric organic acids that are able to biochemically react with both acids or bases.’
    • ‘The presence of both of these ions makes water an amphoteric substance.’
    • ‘The isolation of morphine from opium takes advantage of the amphoteric nature of the alkaloid, since morphine is a phenolic amine.’
    • ‘Finally, amphoteric detergents have either a positively or negatively charged ion, depending on the pH of the system they are incorporated into.’
    • ‘Proteins can also be amphoteric compounds - a compound that can take on a negative or positive charge depending on the surrounding conditions.’


Mid 19th century: from Greek amphoteros, comparative of amphō both, + -ic.