extremely useful synonym valuable 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. compare valuable Invaluable means ‘very valuable or useful’. The opposite of valuable is valueless or worthless. More Like This Words that look like opposites, but aren’t different/indifferent, interested/disinterested, famous/infamous, flammable/inflammable, savoury/unsavoury, sensible/insensible, valuable/invaluableSee worksheet. Word Familyvalue noun verbvaluable adjectiveinvaluable adjective (≠valueless)valuables nounExtra examples This technology is invaluable for pupils with poor sight. You will find their help absolutely invaluable. Your support has been invaluable to us.