Definition - What does Prajapati mean?
Prajapati is the supreme creator in the Vedic period of Hinduism, who was responsible for the creation and preservation of life. Originally, the term, prajapati, was used in reference to many figures; however, it became a term used for only a single deity. This deity is the lord of all creatures and identified with Vishnu, Shiva, different mythical progenitors, or the personifications of the sun and fire.
In Sanskrit, praja means "offspring" and pati means "lord" or "master." In the Vedas and Upanishads, prajapati is used to describe the creator of all living beings.
Yogapedia explains Prajapati
In the "Rig Veda," one of the sacred Vedic Sanskrit hymns, Prajapati is described as the first god and creator of all other gods and beings. He was identified with the god, Brahma, and, by some, it was believed that Prajapati was Brahma. The story in the Vedas states that Prajapati was created in the form of a golden egg and, once hatched, he used his first three breaths to create the god of fire (Agni), the god of lightning (Indra) and the sacred plant, soma. He created planets, seasons, air, earth and sky. He had a daughter named Usas, the goddess of the dawn, and, through her, he evolved into the father of all living beings. Some people believe that Vishnu and Krishna are Prajapati's reincarnates, but a greater belief is still that Prajapati is Brahma.