Definition of "compositor"

Thus, when he drew up instructions in lawyer language […] his clerks […] understood him very well. If he had written a love letter, or a farce, or a ballade, or a story, no one, either clerks, or friends, or compositors, would have understood anything but a word here and a word there.

1892, Walter Besant, “Prologue: Who is Edmund Gray?”, in The Ivory Gate […], New York, N.Y.: Harper & Brothers, […]

All Spaniards, we discovered, knew two English expressions. One was 'O.K., baby', the other was a word used by the Barcelona whores in their dealings with English sailors, and I am afraid the compositors would not print it.

1938 April, George Orwell [pseudonym; Eric Arthur Blair], chapter IV, in Homage to Catalonia, London: Secker & Warburg

However late medieval copyists were supervised — and controls were much more lax than many accounts suggest — scribes were incapable of committing the sort of "standardized" error that was produced by a compositor who dropped the word "not" from the Seventh Commandment and thus created the "wicked" Bible of 1631.

1983, Elizabeth L. Eisenstein, The Printing Revolution in Early Modern Europe, Cambridge University Press, Second edition, 2005, p. 56