smog UK /smɒɡ/US /smɑɡ/noun 1verb 1forms 3 noun1 •A noxious mixture of particulates and gases that is the result of urban air pollution.A widow since 1967, she lives now in Honolulu because, she says, she can enjoy the Californialike climate without the smog. — 1973 verb1 •(informal) To get a smog check; to check a vehicle or have it checked for emissions.If the car is more than five years old, you'll have to have it smogged before you can register it. formssmogged · smogging · smogs
