Is it ensure, insure, or assure?
1590s, from Middle French ligation, from Late Latin ligationem (nominative ligatio), noun of action from past participle stem of ligare "to bind" (see ligament).
ligation li·ga·tion (lī-gā'shən)n.
The act of binding or of applying a ligature.
The state of being bound.
Something that binds; a ligature.