Can also refer to a cover-up in a figurative sense.
No olvides poner la tapadera en la olla para que la comida no se enfríe.
Don't forget to put the lid on the pot so that the food doesn't get cold.
Cuando abrí la caja, encontré una tapadera que parecía haber sido hecha a mano.
When I opened the box, I found a lid that seemed to have been handmade.