1) Mechanical device 
A copyholder is a device that holds the hand written or printed material being typed by a copy typist. They were used in the past with typewriters and are now used with computers and word processors like Writer or Word. Some copyholders stand independently whilst others are attached to CRT based computer monitors. They can support entire booklets ...
• (n.) One possessed of land in copyhold. • (n.) A device for holding copy for a compositor. • (n.) One who reads copy to a proof reader.
Cop'y·hold`er noun 1. (Eng. Law) One possessed of land in copyhold. 2. (print.) (a) A device for holding copy for a compositor. (b) One who reads copy to a proof reader. 
[n] - mechanical device used in printing
noun mechanical device used in printing; holds the copy for the compositor
a person or thing that holds copy. · a device for holding copy in its place, as on a printer's frame or on a typewriter. · a proofreader's assistant who reads copy aloud or follows it while proof is read for the detection of deviations from it in proof. · a person who holds an estate in copyhold.