laborious

adjective

la·​bo·​ri·​ous lə-ˈbȯr-ē-əs 

1

a

: involving, requiring, or characterized by hard and sustained effort : arduous

Overland travel was not an adventurous communal leap, but a laborious, individual trek.

—Daniel J. Boorstin

Making a telescope mirror is a long and laborious process.

—David Devoss and Eric Sander

b

: characterized by long, detailed elaboration : tedious

Much of the middle of the book is a laborious account of the scouring of the ocean floor that led to the discovery of the Titanic.

—The Economist

2

: devoted to labor : industrious

We have the greatest riches, the greatest fertility, … the most laborious population.

—Joseph Conrad

laboriously adverb

laboriousness noun

Synonyms

• active
• assiduous
• bustling
• busy
• diligent
• employed
• engaged
• hopping
• industrious
• occupied
• sedulous
• tied-up
• working

Examples of laborious in a Sentence

a slow and laborious process

the volunteers have been commendably laborious in their cleanup of the beach

Recent Examples on the Web

These are laborious undertakings that require substantially more staff (with specialized training, no less) than a dinner-only joint. —Heather Sperling, Los Angeles Times, 14 May 2024

This low data quality makes normalization and curation for diverse data sources laborious and expensive. —William Mullane, USA TODAY, 12 May 2024

Word History

First Known Use

14th century, in the meaning defined at sense 2

Kids Definition

laborious

adjective

la·​bo·​ri·​ous lə-ˈbōr-ē-əs 

-ˈbȯr-

1

: devoted to work : industrious

2

: requiring hard effort

laboriously adverb

laboriousness noun