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 PDF — $25 TOEFL PDF — $25 IELTS PDF — $25 ← invalidate invariably → Study tips featuring "invaluable" TOEFL Academic Vocabulary: Study by Topic How Context Clues Save You on the SAT Boost Your IELTS Writing With Precise Vocabulary 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