/ ləˈbɔːriəs; NAmE / adjective
taking a lot of time and effort
SYN onerous , taxing :
a laborious task / process
Checking all the information will be slow and laborious.
► la·bori·ous·ly adverb
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WORD ORIGIN
late Middle English (also in the sense industrious, assiduous ): from Old French laborieux , from Latin laboriosus , from labor labour.