Darcy was not of a disposition in which happiness overflows in mirth; and Elizabeth, agitated and confused, rather knew that she was happy than felt herself to be so; for, besides the immediate embarrassment, there were other evils before her.
-- Jane Austen, Pride and Prejudice, 1813
Thus adjured, Lily turned her eyes on the spectacle which was affording Mr. Dorset such legitimate mirth.
-- Edith Wharton, House of Mirth, 1905
Mirth comes from the Old English myrgth and shares a root with the word merry.