This is the 4646th most frequent French word.
organisés
Organized.
Here, 'organisés' acts as a past participle used as an adjective describing 'les événements', indicating that they were properly managed.
Les événements étaient bien organisés.
The events were well organized.
In this sentence, 'organisés' is the past participle of the verb 'organiser', agreeing in gender and number with the subject 'nous'. It conveys the completion of the action of organizing.
Nous avons organisés plusieurs festivals cette année.
We have organized several festivals this year.
Here, 'organisés' is used as an adjective, describing the subjects 'elles' and showing their systematic way of working. A feminine form 'organisées' should actually be used.