assiduous

/əˈsɪdjuːəs/adjective

Showing steady, careful effort; diligent and persistent in one's work.

Example sentence

“Her assiduous preparation paid off when she passed the exam easily.”

Formal; the adverb "assiduously" may be met more often than the adjective. "Diligent" is the plainer choice.

Related words

assignmentThe act of handing out a job or duties, or the task that is given.assertiveConfident and direct in expressing opinions or claiming one's rights, without being aggressive.assuageTo ease or soften something unpleasant, such as pain, hunger, or a strong emotion.assembleTo fit parts together into a whole, or to gather in one place.asthmaA chronic breathing disorder in which the airways can suddenly tighten, often triggered by allergens, cold air, exercise, or stress.aspireTo aim for or eagerly wish to achieve a goal.