Definition of "Indenture" :

noun: the space left between the margin and the start of an indented line

noun: a contract binding one party into the service of another for a specified term

noun: formal agreement between the issuer of bonds and the bondholders as to terms of the debt

noun: a concave cut into a surface or edge (as in a coastline)

verb: bind by or as if by indentures, as of an apprentice or servant

"An indentured servant."