tapper

noun

1.
a tavern keeper who taps kegs or casks
tapster
Derived from:
tap
2.
a person who strikes a surface lightly and usually repeatedly
Derived from:
tap
3.
a worker who uses a tap to cut screw threads
Derived from:
tap
4.
someone who wiretaps a telephone or telegraph wire
phone tapper wiretapper
Derived from:
tap
5.
a dancer who sounds out rhythms by using metal taps on the toes and heels of the shoes
tap dancer
Derived from:
tap