firewall (n.)(colloquial) the application of maximum thrust;
he moved the throttle to the firewall
firewall (n.)(computing) a security system consisting of a combination of hardware and software that limits the exposure of a computer or computer network to attack from crackers; commonly used on local area networks that are connected to the internet;
firewall (n.)a fireproof (or fire-resistant) wall designed to prevent the spread of fire through a building or a vehicle;
)window.location='https://www.paypal.com/cgi-bin/webscr?cmd=_donations&business=byronic106@yahoo.com&lc=US&item_name=Donation+to +Help+Keep+Etymonline+Free+and+Open&no_note=0&cn=&curency_code=USD&bn=PP-DonationsBF:btn_donateCC_LG.gif:NonHosted'){kind=link}