To plunge something briefly into liquid, or in basketball, to forcefully put the ball through the hoop from above.
Originally from Pennsylvania Dutch dunke meaning 'to dip'. The word entered English in the early 1900s through the religious practice of dunking for baptism, later extending to the basketball meaning in the 1930s.
The word 'dunk' beautifully demonstrates semantic broadening - from a religious ritual of baptism by immersion to the athletic spectacle of slam dunking, showing how language adapts to new cultural contexts while maintaining its core meaning of forceful downward motion into something.
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