This is the 914th most frequent Hebrew word.
לסיום
"To conclude" or "in conclusion."
Here, 'לסיום' is used to signify the speaker is reaching the conclusion of their statement.
לסיום, אני רוצה להודות לכל הנוכחים.
In conclusion, I want to thank everyone present.
In this sentence, 'לסיום' indicates the time at the conclusion of the event, the course.
לסיום הקורס, קיבלנו תעודות.
At the end of the course, we received certificates.
Here, 'לסיום' is used to denote the timing of discussing or addressing the important matters, which is suggested to be at the end.