This word is acceptable for play in the US & UK dictionaries that are being used in the following games:

• Lexulous
• Wordscraper
• Wordosaur

adj. Marked by or requiring long, hard work: spent many laborious hours on the project.

adj. Hard-working; industrious.

adj. Requiring much physical effort; toilsome.

adj. Mentally difficult; painstaking

adj. Industrious.

adj. Requiring labor, perseverance, or sacrifices; toilsome; tiresome.

adj. Devoted to labor; diligent; industrious.

Requiring much labor, exertion, or perseverance; toilsome; not easy: as, laborious duties; a laborious undertaking.

Using exertion; practising labor; diligent in work or service; assiduous: as, a laborious husbandman or mechanic; a laborious minister or pastor.

Characterized by labor or effort; marked by or manifesting labor.

Synonyms Difficult arduous, wearisome, fatiguing, onerous.

Industrious, painstaking, active, hard-working.

adj. characterized by effort to the point of exhaustion; especially physical effort

"The unfortunate reputation that writing often bears as being boring and laborious is likely a result of people writing about uninteresting topics and doing so only out of necessity."

effortful   

industrious   

toilsome    tiresome    diligent    industrious   

glorious    inglorious    meritorious    notorious    victorious   

tedious    arduous    industrious    careful    painstaking    scientific    hazardous    difficult    ingenious    profitable