risibility(n = noun.attribute) - a disposition to laugh;
is a kind of good nature
Derived form adjective risible₁

   The quality of being risible; as, risibility is peculiar to the human species. [1913 Webster]
"A strong and obvious disposition to risibility." [1913 Webster]

N  rejoicing, exultation, triumph, jubilation, heyday, flush, revelling, merrymaking, jubilee, paean, Te Deum, congratulation, smile, simper, smirk, grin, broad grin, sardonic grin, laughter (amusement), risibility, derision, Momus, Democritus the Abderite, rollicker, rejoicing, jubilant, exultant, triumphant, flushed, elated, pleased, delighted, tickled pink, amused, cheerful, laughable, Int, hurrah!, Huzza!, aha!, hail!, tolderolloll!, Heaven be praised!, io triumphe!, tant mieux!, so much the better, the heart leaping with joy, ce n'est pas etre bien aise que de rire, Laughter holding both his sides, le roi est mort, vive le roi, with his eyes in flood with laughter.