laughter Copy link Outline 1. rīsus, ūs2. căchinnātio (indecorous l. • laughter: 1. rīsus, ūs: to excite l., r. movere, Cic.: v. laugh (subs.). 2. căchinnātio (indecorous l.: rare): Cic. Tusc. 4, 31, 66. (Also, if the act be meant, cachinnus: v. laugh, subs.)