collibert

from The Century Dictionary.

• noun A socman; a tenant holding in fee socage, but obliged, as long as ho held, to render some customary service or due.
• noun One of a despised race formerly existing in several parts of France, afterward chiefly found in Poitou, where they lived in boats on the rivers, but now nearly extinct: probably so called from the ancient class of French serfs of that name.