Term: air pollution: pollution of the atmosphere
Broader: abstraction: a general concept formed by extracting common features from specific examples | Unrelated: danaea: fairly small terrestrial ferns of tropical America
Broader: abstraction: a general concept formed by extracting common features from specific examples | Unrelated: crystal: a protective cover that protects the face of a watch
Broader: abstraction: a general concept formed by extracting common features from specific examples | Unrelated: bun: small rounded bread either plain or sweet
Broader: abstraction: a general concept formed by extracting common features from specific examples | Unrelated: sour dock: European sorrel with large slightly acidic sagittate leaves grown throughout north temperate zone for salad and spring greens
Broader: abstraction: a general concept formed by extracting common features from specific examples | Unrelated: small change: a trifling sum of money
Broader: abstraction: a general concept formed by extracting common features from specific examples | Unrelated: hinging post: the gatepost on which the gate is hung
Broader: abstraction: a general concept formed by extracting common features from specific examples | Unrelated: rift valley: a valley with steep sides; formed by a rift in the earth's crust
Broader: abstraction: a general concept formed by extracting common features from specific examples | Unrelated: rock opera: albums of rock music that aspired to the status of art; first appeared in the 1960s
Broader: abstraction: a general concept formed by extracting common features from specific examples | Unrelated: unleaded gasoline: gasoline that has not been treated with a lead compound
Broader: abstraction: a general concept formed by extracting common features from specific examples | Unrelated: mako: powerful mackerel shark of the Atlantic and Pacific