MEANING:
noun: The practice of making unfounded accusations against someone.
ETYMOLOGY:
After US senator Joseph McCarthy (1909-1957) known for making unsubstantiated claims accusing people of being Communists, spies, and disloyal. Earliest documented use: in 1950 in a cartoon by Herbert Block.
USAGE:
"This is the greatest case of rampant McCarthyism to ever hit organized sports. ... There was no hard evidence that three other first-timers on the ballot used steroids, but that didn't keep the Baseball Writers Association of America (BBWAA) voters from denying them entry to the Hall.