n. A slave-dealer; someone who seizes another person to hold that person as a slave or sell that person into slavery; more loosely: a slaveholder.
the GNU version of the Collaborative International Dictionary of English
n. A person who steals or kidnaps a human being or beings.
The Century Dictionary and Cyclopedia
n. One who steals human beings, generally for the purpose of selling them as slaves; a kidnapper.
Word Usage
"Christian disciple, fulfilling in righteousness and love a Christian duty, then slavery is right; if slavery is wrong, then every slave-holder is a manstealer, and should be excommunicated as such without asking any further questions."