SAT GRE IELTS vigilant Definition Careful and watchful to avoid danger or mistakes. Example "Be vigilant when walking alone at night." Sign in to save SAT Quiz → GRE Quiz → IELTS Quiz → ← vigilance vignette → Study tips featuring "vigilant" Let the Argument Reveal Unfamiliar Word Meanings Study the Exact Words Examiners Use Group Words Together by Emotional 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