Entry 3 senses · 2 variants Webster, 1913 Nestling /nĕs'-tlĭng/ · Nes·tling · IPA /ˈnɛstlɪŋ/ n. a. 01 n. A young bird which has not abandoned the nest. 1. A young bird which has not abandoned the nest. 2. A nest; a receptacle.[Obs.] 02 a. Newly hatched; being yet in the nest. 1. Newly hatched; being yet in the nest.