SAT earnest Definition Serious in intention or purpose; showing sincerity. Example "He made an earnest promise to return the borrowed money." Sign in to save SAT Quiz → ← eager earring → Study tips featuring "earnest" Let the Argument Reveal Unfamiliar Word Meanings Map the Author's Attitude Before Reading Questions Stop Skipping Words and Read the Tone Related words SAT antonym SAT abase SAT abdicate SAT abdomen SAT abduction SAT abet SAT abeyance SAT abject SAT abjure SAT ablution SAT abnegate SAT abnormal