Calme.
Very calm is "très calme" in French
du calme!
Je suis calme.
je suis calme
Du calme, du calme.
tu dois te calmer / vous devez vous calmer
j'avais besoin de rester calme
You can say "calm down" in different ways such as "take a deep breath," "relax," or "stay calm."
In Hawaiian, you would say "hoʻomaluhia".
calmer is a verb (to calm, to calm down); it has no masculine nor feminine in French.
calmant, calmante
"Calm" in Hawaiian is "maluhia."