[f. LAP v.4 + -ER1.] One who uses a lap or lapidary’s wheel.

1

1877.  Gee, Pract. Gold-worker, 178. The lapper produces the plain and diamond-shaped surfaces by the rotary action of the lapidary’s wheel.

2

1896.  Mod. Advt., Lapper wanted, to fill in spare time with polishing.

3