This is the 1050th most frequent French word.
puisque
"Since" or "because."
"Puisque" is used here to introduce a reason that is already established, emphasizing the speaker's presumption that the listener agrees with this reasoning.
Puisque tu es ici, profites-en pour nous aider.
Since you are here, take the opportunity to help us.
"Puisque" introduces an evident cause or reason that justifies her decision to stay home.
Elle a décidé de rester à la maison, puisqu'il pleuvait beaucoup.
She decided to stay home since it was raining heavily.
"Puisque" is employed to present the cause (finishing earlier) leading directly to the consequence (being able to leave earlier).