Noun, pl. hatchlings
1. A bird or reptile that has newly emerged from an egg. (wikipedia.org)
2. A newly hatched bird, reptile or other animal that has emerged from an egg. (wiktionary.org)
Word origin: From Middle English hachen (early 13c.), probably from an unrecorded Old English *hæccan, of unknown origin, related to Middle High German, German hecken “to mate” (used of birds). + diminutive suffix –ling.