demise

From Middle English demyse, dimise, dimisse, dymyse, from Middle French démise, the feminine singular past participle of démettre (“to put down, relinquish”); from Latin dēmissa, feminine singular of perfect passive participle of dēmittō. The "death" and "end" senses derive by way of euphemism from the legal sense, as a person's death was a common way that the legal demise could be accomplished.

The verb is from Middle English dimisen, from the noun.