Entry Word: laborious

Function: adjective

Meaning: 1 involved in often constant activity <the volunteers have been commendably laborious in their cleanup of the playground> — see busy 1
2 requiring considerable physical or mental effort <the workers soon wearied of their laborious tasks> — see hard 2
3 requiring much time, effort, or careful attention <the students spent hours researching and writing the laborious report> — see demanding 1