fasten or close securely

he folded it, sealed the envelope, and walked to the postbox

apply a non-porous coating to (a surface) to make it impervious

the pine boarding should be sealed with polyurethane

fry (food) briefly at a high temperature to prevent it from losing moisture during subsequent cooking

heat the oil and seal the lamb on both sides

conclude, establish, or secure (something) definitively

to seal the deal he offered Thornton a place on the board of the company

fix a piece of wax or lead stamped with a design to (a document) to authenticate it