early 15c., "one who squanders or wastes," agent noun from consume. In economics, "one who uses up goods or articles, one who destroys the exchangeable value of a commodity by using it" (opposite of producer), from 1745.
Consumer goods is attested from 1890. In U.S., consumer price index calculated since 1919, tracking "changes in the prices paid by urban consumers for a representative basket of goods and services" [Bureau of Labor Statistics]; abbreviation CPI is attested by 1971.
"Public agitation for greater safety and higher quality in consumer goods" [OED], 1969, in reference to the concerns and methods of U.S. lawyer and consumer advocate Ralph Nader (b. 1934) + -ism.
1560s, "buying and selling, act of transacting business in a market," verbal noun from market (v.). Meaning "produce bought or sold at a market" is from 1701. The business sense, "process of moving goods from producer to consumer with emphasis on advertising and sales," is attested by 1897.
1748, "philosophy that nothing exists except matter" (from French matérialisme); see material (n.) + ism. As this naturally tended toward "opinion or tendency based upon purely material interests," it came to be used by late 19c. for any low view of life (opposed to idealism). As "a way of life based entirely on consumer goods," by 1930.