IPA: /kəmˈpliːʃən/
KK: /kəmˈpliːʃən/
The act of finishing something or bringing it to an end.
The completion of the project was celebrated by the entire team.
Completion → It is formed from "com-" (meaning together) and "plere" (meaning to fill). The word "completion" refers to the act of filling something up or bringing it to a state of fullness or finish.
Think of 'filling something up' ('plere') 'together' ('com-') — that's why completion means bringing something to its full state.