sealed vs certain

sealed and certain both are adjectives.

Word	Noun	Adjective	Verb	Adverb
sealed	No	Yes	No	No
certain	No	Yes	No	No

As adjectives, sealed and certain are synonyms defined as:

sealed (adjective)	certain (adjective)
closed or secured with or as if with a seal	established beyond doubt or question; definitely known
established irrevocably	having or feeling no doubt or uncertainty; confident and assured
undisclosed for the time being	certain to occur; destined or inevitable
determined irrevocably	established irrevocably
apply a non-porous coating to something so as to ensure it is impervious	exercising or taking care great enough to bring assurance
covered with a waterproof coating	definite but not specified or identified
(of walls) covered with a coat of plaster	reliable in operation or effect