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
a serve that strikes the net before falling into the receiver's court; the ball must be served again
leave unchanged; "let it be"
actively cause something to happen; "I let it be known that I was not interested"
make it possible through a specific action or lack of action for something to happen; "This permits the water to rush in"; "This sealed door won't allow the water come into the basement"; "This will permit the rain to run off"