tapper

(noun) a tavern keeper who taps kegs or casks. Synonyms: tapster.

(noun) a person who strikes a surface lightly and usually repeatedly. Example: "Finger tappers irritated her."

(noun) a worker who uses a tap to cut screw threads.

(noun) someone who wiretaps a telephone or telegraph wire. Synonyms: wiretapper, phone tapper.

(noun) a dancer who sounds out rhythms by using metal taps on the toes and heels of the shoes. Synonyms: tap dancer.