Definitions of Dunker:

• noun:   an adherent of Baptistic doctrines (who practice baptism by immersion)
• noun:   a basketball player who is able to make dunk shots
• noun:   an eater who dips food into a liquid before eating it

  Example: "He was a dunker--he couldn't eat a doughnut without a cup of coffee to dunk it in"

• name:  A surname (very rare: popularity rank in the U.S.: #23090)