firewall Syllabification: (fire·wall)Pronunciation: /ˈfīrˌwôl/Translate firewall | into Italian Definition of firewall noun a wall or partition designed to inhibit or prevent the spread of fire. Computing a part of a computer system or network that is designed to block unauthorized access while permitting outward communication. another term for Chinese wall.firewall in other Oxford dictionaries Definition of firewall in the British & World English dictionary