hĭlărĭtūdo

ĭnis, f.

hilaris

I. cheerfulness, merriment (ante-class. for the class. hilaritas): numquam ego te tristiorem Vidi esse: quid cedo tam abhorret hilaritudo? Plaut. Cist. 1, 1, 56: onera te hilaritudine, id. Mil. 3, 1, 83: ut in ocellis hilaritudo est! id. Rud. 2, 4, 8.
Lewis & Short
A Latin Dictionary, 1879
An open-access project