SAT TOEFL IELTS invaluable Definition Extremely useful; too valuable to be measured. Example "Her advice was invaluable during the crisis." Sign in to save SAT Quiz → TOEFL Quiz → IELTS Quiz → ← invalidate invariably → Study tips featuring "invaluable" Let the Argument Reveal Unfamiliar Word Meanings Study the Exact Words Examiners Use Map Each Word Into a Connected Network 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