Quick answer
Vishnu is a boy name meaning "all-pervasive".
Pronunciation: Sanskrit /ˈʋɪʂ.ɳu/; English /ˈvɪʃ.nu/; Malayalam /ˈʋiʂ.ɳu/; Tamil /ˈʋɪʂ.ɳʊ/; Hindi /ˈʋɪʂ.ɳuː/.
Meaning and history
Probably means "all-pervasive" in Sanskrit, from विष् (viṣ) meaning "to pervade, to spread through". The Hindu god Vishnu is the protector and preserver of the universe, usually depicted as four-armed and blue-skinned. His wife is Lakshmi. Though he appears in the Rigveda, he features more prominently in post-Vedic texts. The great heroes Krishna, Rama, Narasimha and others are regarded as avatars of Vishnu. Vaishnavism, the largest denomination within Hinduism, views Vishnu and his avatars as the supreme god.
Notes and context
Usage: hinduism, malayalam, kannada, telugu, tamil, hindi, marathi | Sanskrit: विष्णु; Malayalam: വിഷ്ണു; Kannada: ವಿಷ್ಣು; Telugu: విష్ణు; Tamil: விஷ்ணு