ridiculum
From LSJ
ridiculum ridiculi N N :: joke, piece of humor
rīdĭcŭlum,¹⁴ ī, n. (ridiculus), ce qui fait rire, mot plaisant, plaisanterie, bouffonnerie : Cic. Or. 87 ; 88 ; per ridiculum Cic. Off. 1, 134, en plaisantant ; pl., Cic. de Or. 2, 237 ; 286.