Etymology: < French métayer (1150 in Old French as moitoier ) < meitié , moitié moiety n. + -ier -ier suffix, after post-classical Latin medietarius person owing half tithes (860), hereditary tenant farmer entitled to half the yield (1007; also as adjective in sense ‘granted as a tenancy at a rate of half the crop’ (866)) < classical Latin medietās mediety n. + -ārius -ary suffix1. Compare mezzadria n.
A farmer who holds land under the métayage system. (OED)
which brings us to métayage:
Etymology: < French métayage (1840; compare Middle French moitoiage agreement to share in halves (1396)) < métayer métayer n. + -age -age suffix. Compare earlier metaying n.
A system of land tenure in which the farmer pays a certain proportion (usually half) of the produce to the landowner as rent, and the owner provides (a part of) the stock and seed. (OED)
"The legal form of service was theoretically far different; in practice, task-work or "cropping" was substituted for daily toil in gangs; and the slave gradually became a metayer, or tenant on shares, in name, but a laborer with indeterminate wages in fact."
- W.E.B. DuBois, The Souls of Black Folk, 1903