Plagiarius

PLAGIARIUS, civil law. He who fraudulently concealed a freeman or slave who belonged to another.
     2. The offence itself was called plagium.
     3. It differed from larceny or theft in this, that larceny always implies that the guilty party intended to make a profit, whereas the plagiarius did not intend to make any profit. Dig. 48, 15, 6; Code, 9, 20, 9 and 15.