An arrangement between two countries, states, or other administrative regions, that allows free air travel of residents between them while otherwise keeping their borders closed to travellers from outside the bubble.

plural of flight bubble

(informal) A condition where one experiences discomfort, bloating, and cramping in the stomach or digestive tract due to gases caused by extreme hunger or explosive pre-diarrhoea.

Synonym of bubble guts

plural of hubbly-bubbly

(idiomatic) To disillusion; to disabuse someone of a false notion or rationalization that has grown comfortable.

(business, history) A historic speculative bubble based around the Internet, covering roughly 1997–2000.

Synonym of dot-com bubble

(medicine, medical genetics) Severe combined immunodeficiency (SCID), a genetic disorder resulting in extreme vulnerability to infectious diseases.

Synonym of bubble boy disease