adj. 1 serious, solemn, grave, sober, intense, steady, resolute, resolved, firm, determined, assiduous, sincere, dedicated, committed, devoted, thoughtful He made an earnest promise to do his best 2 zealous, ardent, diligent, assiduous, industrious, hard-working, devoted, eager, conscientious, keen, fervent, fervid, enthusiastic, passionate Burbridge is an earnest pupil 3 earnest-money. deposit, down payment, binder, handsel, guarantee, security, pledge The company paid $10,000 earnest-money to secure the bid
n. 4 in earnest. serious, sincere She said she would come, but I doubt whether she was in earnest