Definition of "Tapper" :
noun: a dancer who sounds out rhythms by using metal taps on the toes and heels of the shoes
noun: someone who wiretaps a telephone or telegraph wire
noun: a worker who uses a tap to cut screw threads
noun: a person who strikes a surface lightly and usually repeatedly
"Finger tappers irritated her."
noun: a tavern keeper who taps kegs or casks