means A young dog, typically under a year old, still growing into its paws and personality.

from From Middle English, borrowed from Old French 'poupée' meaning 'doll' or 'plaything' (itself from Latin 'pupa,' a girl or a doll). The same root gives us 'puppet' — a fitting cousin, since the word originally meant a lap dog kept as a toy or trinket. Over time it slid from 'cute small dog' to specifically 'young dog,' and the underlying 'pupa' lives on in biology as the doll-like resting stage of insects.