Definify.com
Webster 1913 Edition
Rapper
1.
One who, or that which, raps or knocks; specifically, the knocker of a door.
Sterne.
2.
A forcible oath or lie.
[Slang]
Bp. Parker.
Webster 1828 Edition
Rapper
RAP'PER
,Noun.
1.
One that raps or knocks.2.
The knocker of a door. [Not in common use.]3.
An oath or a lie. [Not in use.]