expression, suru verb (irregular)
bring to an end; close the curtain on
Figurative expression meaning to conclude or finish something, often used for events, projects, or periods. The literal image is of lowering a theater curtain.
See also: 幕になる (まくになる)
長かった会議もようやく幕にした。
We finally brought the long meeting to an end.
He decided to close the curtain on that incident.