a mechanism consisting of a metal honeycomb through which hot fluids circulate; heat is transferred from the fluid through the honeycomb to the airstream that is created either by the motion of the vehicle or by a fan
heater consisting of a series of pipes for circulating steam or hot water to heat rooms or buildings
eject or send out in large quantities, also metaphorical; "the volcano spews out molten rocks every day"; "The editors of the paper spew out hostile articles about the Presidential candidate"