Definition of decrescent in English:

decrescent

adjective

  • (of the moon) waning:

    ‘the keen-sighted watcher may catch a glimpse of the slender decrescent moon’
    • ‘The waning moon was "decrescent".’

Origin

Early 17th century: from Latin decrescent- growing less, from the verb decrescere (see decrease).

Pronunciation:

decrescent

/dɪˈkrɛs(ə)nt/