short wave: a radio wave with a wavelength less than 100 meters (a frequency greater than 3 megahertz)
radio wave: an electromagnetic wave with a wavelength between 0.5 cm to 30,000 m
stamp act: an act passed by the British Parliament in 1756 that raised revenue from the American Colonies by a duty in the form of a stamp required on all newspapers and legal or commercial documents; opposition by the Colonies resulted in the repeal of the act in 1766