This is the 11114th most frequent Catalan word.
sufocar
To suffocate or stifle.
In this context, 'sufocar' is used literally to mean causing a physical condition of impeded breathing.
El fum del foc va començar a sufocar els ocupants de la casa.
The smoke from the fire began to suffocate the occupants of the house.
This usage of 'sufocar' is figurative, referring to suppressing a characteristic or aspect of someone's personality.
No vull sufocar la seva creativitat amb massa normes.
I don't want to stifle their creativity with too many rules.
Here, 'sufocar' is used metaphorically, meaning to harm the plants by overwatering.