extremely useful invaluable information invaluable to/for somebody/something The book will be invaluable for students in higher education. invaluable in something The research should prove invaluable in the study of children's language. Invaluable means “very valuable or useful.” The opposite of valuable is valueless or worthless. compare valuable
value noun verbvaluable adjectiveinvaluable adjective (≠valueless)valuables noun
Check pronunciation: invaluable