Definition of rare bird in English:

rare bird

noun

  • An exceptional person or thing; a rarity.

    ‘Irish tenors such as he are rare birds’
    • ‘And there certainly are nice people in sales professions, even those rare birds who will sacrifice their commissions to make sure you get what you truly need or want.’
    • ‘Though men far outnumber women at both resorts, we feel welcome, even special, like rare birds.’
    individualist, individual, eccentric, nonconformist, free spirit, bohemian, maverick, oddity
    View synonyms

Origin

Translating Latin rara avis (Juvenal's Satires, vi.165: rara auis in terris nigroque simillima cycno, ‘[a good woman is] a rare bird in this world and very like a black swan’).