In the Vedic Naamkaran tradition, a baby born in Punarvasu nakshatra is named with a sound from its four padas.
Lord Jupiter, deity Aditi, Deva gana. The name starts with the syllable of the pada the Moon occupied at birth - which is why the pada, and so the syllable, needs an accurate birth time.
The syllables are the jyotisha almanac's table (the avakahada chakra). The Dharmasindhu (1888, p. 133) records that some name a child by it, and says the srauta and grihya texts do not agree; no text stating the table itself was found.
Names follow the Vedic Naamkaran (Namakaran) method based on the Moon’s birth nakshatra. Meanings are traditional.