cerrar.

to close, to shut

No olvides cerrar la puerta.

Cierra la ventana, por favor.

to shut down, to close down

Quieren cerrar tu negocio.

to turn off, to shut off (to rotate a tap or valve so as to interrupt the outflow of liquid or gas)

cerrar el grifo

to turn off (a light or electrical device)

Puedes cerrar la luz?

to enclose

to lock, to lock up

to seal, to close (e.g. a deal, a breach, a rift)

to close up, to close off (e.g. a wound)

to close, to conclude, to end

to close (itself) (e.g., a store, a door)

to close off (oneself)

Me cierro cuando alguien empieza a insultarme delante de los demás.

to close