laboriosus

From labor (“work, exertion”) +‎ -ōsus. However, the inserted -i- is enigmatic. It may be a result of analogy: cūra : cūriōsus = labor : ?

• (Classical Latin) IPA^(key): /la.boː.riˈoː.sus/, [ɫ̪äboːriˈoːs̠ʊs̠]
• (modern Italianate Ecclesiastical) IPA^(key): /la.bo.riˈo.sus/, [läboriˈɔːs̬us]

labōriōsus (feminine labōriōsa, neuter labōriōsum, superlative labōriōsissimus, adverb labōriōsē); first/second-declension adjective

1. laborious, toilsome, demanding
   • c. 84 BCE – 54 BCE, Catullus, Carmina 1.1–7:

     Cui dōnō lepidum novum libellum
     āridō modo pūmice expolītum?
     Cornēlī, tibi: namque tū solēbās
     meās esse aliquid putāre nūgās
     jam tum, cum ausus es ūnus Ītalōrum
     omne aevum tribus explicāre cartīs
     doctīs, Jūpiter, et labōriōsīs.

2. industrious, hard-working

First/second-declension adjective.

• labōriōsē

• labor
• labōrō

• English: laborious
• French: laborieux
• Italian: laborioso
• Portuguese: laborioso
• Spanish: laborioso

• “laboriosus”, in Charlton T. Lewis and Charles Short (1879) A Latin Dictionary, Oxford: Clarendon Press
• “laboriosus”, in Charlton T. Lewis (1891) An Elementary Latin Dictionary, New York: Harper & Brothers
• laboriosus in Charles du Fresne du Cange’s Glossarium Mediæ et Infimæ Latinitatis (augmented edition with additions by D. P. Carpenterius, Adelungius and others, edited by Léopold Favre, 1883–1887)
• laboriosus in Gaffiot, Félix (1934) Dictionnaire illustré latin-français, Hachette.