Both Uses of
perish
in
Beowulf - (translated by: Gummere)
- Nor took from that dwelling the duke of the Geats save only the head and that hilt withal blazoned with jewels: the blade had melted, burned was the bright sword, her blood was so hot, so poisoned the hell-sprite who perished within there.†
perished = died, was destroyed, or ceased to exist
- Now further it fell with the flight of years, with harryings horrid, that Hygelac perished,{29c}and Heardred, too, by hewing of swords under the shield-wall slaughtered lay, when him at the van of his victor-folk sought hardy heroes, Heatho-Scilfings, in arms o'erwhelming Hereric's nephew.†
*
Definition:
to die -- especially in an unnatural way
or:
to be destroyed or cease to exist
or:
to be destroyed or cease to exist
You may encounter an informal expression, "Perish the thought." It means that the speaker hopes the thought will cease to exist and the thing it represents will never happen.