Pullus

Pullus is a Latin noun used in classical and medieval texts to denote the young of an animal, especially a chick or hatchling. In broad usage, it referred to immature offspring in various species, distinguishing the juvenile stage from the adult. The term is masculine, with the plural pulli, and appears in zoological descriptions as a general label for a newly hatched or very young animal.

In historical biology and natural history, pullus appeared in descriptions of birds and other livestock to indicate the early life stage. It is not a formal taxonomic rank, but rather a descriptive term that could accompany a species name or a description, indicating that the subject was in a juvenile state. Because it originates from Latin, pullus has influenced later scientific and scholarly language, even if the term itself is not commonly used in modern formal nomenclature.

Modern usage tends to favor more precise terms such as chick, hatchling, fledgling, or juvenile, depending on the species and context. In English, derivatives and related words tied to young poultry—such as pullet for a young female chicken—reflect the historical Latin vocabulary for offspring, though they are not direct continuations in terminology.

See also: chick, hatchling, juvenile, pullet, avian development, precocial and altricial young.