laborious Copy link Outline 1. lăbōriōsus (toilsome2. ŏpĕrōsus (oft. in act. sense, painstaking, industrious3. expr. by lăbor, ŏpĕra, ŏpus, esp. in gen. of quality (L. G. 274) • laborious: 1. lăbōriōsus (toilsome: infreq.): a very extensive and l. work, opus maximum ac laboriosissimum, Liv. 5, 18, fin.: Cic. 2. ŏpĕrōsus (oft. in act. sense, painstaking, industrious: in present sense, less strong than preced.): a tough and l. task, spissum et o. opus, Cic. Q. Fr. 2, 14. Join: (labor) operosus et molestus, Cic. N. D. 2, 23, 59. 3. expr. by lăbor, ŏpĕra, ŏpus, esp. in gen. of quality (L. G. 274): it (the discipline) is very l., magni est laboris, Cic. de Or. 1, 33, 150: l. as the undertaking was, etsi res erat multae operae ac laboris, Caes. B. G. 5, 11: cf. haud magni operis, Liv. 38, 7, med. (labor indicates toilsomeness, opera exertion): so, how l., quanti laboris, operis! v. labour. For active sense, v. industrious.