LABORIOUS
arduous, backbreaking, grueling, gruelling, hard, heavy, laborious, operose, punishing, toilsome
(adjective) characterized by effort to the point of exhaustion; especially physical effort; “worked their arduous way up the mining valley”; “a grueling campaign”; “hard labor”; “heavy work”; “heavy going”; “spent many laborious hours on the project”; “set a punishing pace”
Source: WordNet® 3.1
Etymology
Adjective
laborious (comparative more laborious, superlative most laborious)
Requiring much physical effort; toilsome.
Mentally difficult; painstaking.
Industrious.
Synonyms
• (requiring effort): painstaking, toilsome, worksome
Source: Wiktionary
La*bo"ri*ous, a. Etym: [L. laboriosus,fr. labor labor: cf. F.
laborieux.]
1. Requiring labor, perseverance, or sacrifices; toilsome; tiresome.
Dost thou love watchings, abstinence, or toil, Laborious virtues all
Learn these from Cato. Addison.
2. Devoted to labor; diligent; industrious; as, a laborious mechanic.
– La*bo"ri*ous*ly, adv.
– La*bo"ri*ous*ness, n.
Source: Webster’s Unabridged Dictionary 1913 Edition