Pracetas primarily refers to the pre-eminently intelligent one, it means observant and intelligent. It is also another name for Varuna, one of the ten Prajapatis one of whom was the father of Valmiki who was also known as Prācetas, the son of Pracetas.
Meaning
Pracetas i.e. प्र + चेतस्, primarily refers to the pre-eminently intelligent one, ordinarily it means observant and intelligent. It is another name for Varuna, one of the ten Prajapatis whose mother was Suvarna According to Valmiki Ramayana, Mahakavi Valmiki was the son of the 10th Pracetas.
Vedic usage
Pracetas are the intelligences which brought consciousness to the outside through the development of the senses which are active as sensations. Senses are the five forces of mind, five different angles of reflection, their formation took place with the help of the Pracetas. In the Rig VedaMantra I.41.1 which reads: The word, pracetas, refers to men of knowledge, the men who are learned and wise. but in the Rig Veda Mantra I.5.7 which reads: The same refers to the Super-conscious Being in whom it is prayed that the impatient seekers be allowed to enter i.e. be merged.
Puranic versions
According to the Puranas, Pracetas was a descendant of Druhyu; he was the son of Duryaman who was the son of Dhrita, the great-great-great grandson of Druhyu. Pracetas had one hundred sons who were the princes of the Mlechchhas, the barbarians of the north. Pracetas is one of the Prajapatis, and an ancient sage and law-giver. It is also said that there were ten Pracetas who were the sons of Prāchinabarhis and great grandsons of Prithu; according to Vishnu Purana they had passed ten thousand years in the great ocean deep in meditation upon Vishnu who made them the progenitors of mankind. The eldest among the ten sons of Prāchinbarhis, collectively known as Pracetas, became the ruler; they cleared forests and made land fit for agriculture; they married the daughters of Soma who begot sons called Daksha Pracetas. There were 49 kings up to Daksha Pracetas. Pracetas emerged from the ocean after their long sojourn, found the earth covered by the trees, they created wind and fire and destroyed the trees. But Brahma requested them not to so and also solemnized their marriage with Marisha, it was their union that gave second body to Daksha Prajapati.