Where does “closure” come from?

closure (Old French) comes from Late Latin clausura, from Latin clausus, from Latin claudere, from Latin claudo, from Proto-Italic klaudō — close.

Ancestry of “closure”, step by step

Step	Language	Word	Meaning
1	Late Latin	clausura	lock, bar, bolt; clasp; lock, bar, bolt; clasp
2	Latin	clausus	closed, inaccessible; having been closed;...
3	Latin	claudere	present active infinitive of claudō;...
4	Latin	claudo	I shut, close, lock; I imprison, confine; I...
5	Proto-Italic	klaudō	close