What does Rishi mean?
From the Sanskrit ऋषि (ṛṣi), 'a seer, sage, inspired poet' — the title of the sages to whom the Vedic hymns were revealed. A firmly established classical word.
What does Atharv mean?
From Sanskrit atharvan (अथर्वन्), the name of the Atharvaveda and of the ancient sage traditionally said to be the first priest of fire. Commonly taken to mean 'knowledge' or evokes the Vedic fire-priest.