Definition of mononym in US English:

mononym

noun

  • A person's name consisting of one word, typically a first name without a surname.

    ‘the villa once belonged to famed Florentine artist Michelangelo Buonarroti, better known by his mononym, Michelangelo’

Origin

Late 19th century (with reference to a one-word term in scientific nomenclature): from mono- + -onym.

Pronunciation

mononym

/ˈmänəˌnim//ˈmɑnəˌnɪm/