1) Something by which a person is bound or obliged to do certain things,
and which arises out of a sense of duty or results from custom, law,
M.E. obligacioun, from O.Fr. obligacion "obligation, duty, responsibility," from L. obligationem "an engaging or pledging," literally "a binding," noun of action from p.p. stem of obligare "to bind, bind up, bandage," from → ob- "to" + ligare "to bind," from PIE root *leig- "to bind."
Fariz, from Mid.Pers. frêz "obligation; duty."