nestling

/ˈnɛstlɪŋ/
noun
  1. A young bird that is not yet able to leave the nest.
    • The nestling opened its beak wide for food.
    • We watched a mother robin feed her nestling.
    • The nestling grew feathers and soon learned to fly.
Antonyms
adjective
  1. Relating to or characteristic of a young bird still in the nest.
    • She studied the nestling behavior of blue jays.
    • The nestling period lasts about two weeks for sparrows.
    • The nestling birds chirped loudly when their mother arrived.