Merriam-Webster refers the term "slam dunk" to the term "dunk shot", which is defined as "a shot in basketball made by jumping high into the air and throwing the ball down through the basket". M-W dates "slam dunk" at 1972, and "dunk shot" as "circa 1961".
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»The dunk is coming back«. Eugene Register-Guard. (Oregon). Associated Press. 1. april 1976. str. 1C.
Doney, Ken (1. april 1976). »'They'll love dunk' - Miller«. Lewiston Morning Tribune. (Idaho). Associated Press. str. 2B.