This is the 949th most frequent French word.
puissent
"Puissent" is the third-person plural subjunctive form of "pouvoir," meaning "may" or "might."
'Puissent' is employed in the subjunctive mood here as an optative expression, a rare usage to express a wish or hope.
Que le ciel et la terre puissent témoigner de notre engagement.
Let the sky and the earth bear witness to our commitment.
The usage of 'puissent' here is subjunctive, following the conjunction 'afin que', which always precedes the subjunctive in French to express purpose or goal.
Nous avons mis tout en oeuvre afin qu’ils puissent réussir leurs projets.
We did everything possible so that they could succeed in their projects.
In this sentence, 'puissent' is used as a subjunctive form following the structure 'il est important que + subjunctive'. The subjunctive is necessary here to express a necessity or wish.