This is the 2424th most frequent French word.
soin
Care.
The word "soin" is used here in the expression "prendre soin de", which means "to take care of".
Il prend soin de ses plantes chaque jour.
He takes care of his plants every day.
The word "soins" is used in its plural form to refer to medical care or treatment.
Elle a reçu des soins de qualité à l'hôpital.
She received quality care at the hospital.
"Soin" here refers to the concept of carefulness or diligence needed for an activity.