This is the 13805th most frequent Spanish word.
sellaron
"Sellaron" means "they sealed."
In this case, 'sellaron' refers to physically closing the boxes to secure their contents.
Los empleados sellaron las cajas antes de enviarlas.
The employees sealed the boxes before shipping them.
Here, 'sellaron' is used figuratively to denote the completion or official confirmation of an agreement.
Los gobiernos sellaron el acuerdo económico en la cumbre.
The governments sealed the economic agreement at the summit.
Here, 'sellaron' is used to signify finalizing or making a pact definitive by an action.