tedious (adj.)youdaoicibaDictYouDict
early 15c., from Old French tedieus, from Late Latin taediosus "wearisome, irksome, tedious," from Latin taedium (see tedium). Related: Tediously; tediousness.
tedium (n.)youdaoicibaDictYouDict
"tediousness," 1660s, from Latin taedium "weariness, irksomeness, disgust," related to taedet "it is wearisome, it excites loathing," and to taedere "to weary," of uncertain origin. Possible cognates are Old Church Slavonic težo, Lithuanian tingiu "to be dull, be listless."