Origin: Latin suffix -ure
Closure has 9 different meanings across 2 categories:
a Gestalt principle of organization holding that there is an innate tendency to perceive incomplete objects as complete and to close or fill gaps and to perceive asymmetric stimuli as symmetric
"When viewing a circle drawn with a small gap, the brain automatically perceives it as a complete shape due to the closure principle."
something settled or resolved; the outcome of decision making
"they finally reached a settlement with the union"
"they never did achieve a final resolution of their differences"
"he needed to grieve before he could achieve a sense of closure"
An event or occurrence that signifies an ending.
"The demolition of the old factory marked a painful closure for the entire community."
In plain English: Closure is the feeling of peace you get when something difficult finally ends and you can stop worrying about it.
"She felt relief after receiving closure about what really happened to her friend."
Usage: Use closure to describe the final resolution of an emotional situation, such as accepting a loss rather than seeking revenge on someone who caused it. It is often confused with completion in business contexts, but here it specifically refers to psychological satisfaction from having loose ends tied up.
From Middle English closure, from Old French closure, from Late Latin clausura, from Latin claudere ("to close"); see clausure and cloture (etymological doublets) and close.