This is the 10406th most frequent French word.
joignent
"Joignent" means "join" (third-person plural of the verb "joindre").
Here, 'joignent' is used to indicate that the subject ('les amis') is performing the action of joining or coming together with another group ('à nous').
Les amis se joignent à nous pour la soirée.
The friends are joining us for the evening.
In this sentence, 'joignent' conveys the idea of connecting or uniting resources ('leurs forces') for a common purpose.
Ils joignent leurs forces pour accomplir ce projet.
They are combining their forces to accomplish this project.
Here, 'joignent' is used to describe the action of connecting or associating different elements ('aspects historiques et contemporains') within a context ('ces discussions').