From Longman Dictionary of Contemporary Englishmagic number/wordmagic number/worda number or word that is particularly important or desired in a particular situation The magic words ‘a million pounds’ will get everyone’s attention. → magic
Examples from the Corpus
magic number/word• The Maharishi's followers say that 7000 is a magic number.• Al knew at once that he had heard A very secret magic word.• Charles would capture one of the boys and only release him if he said the magic word.• This is done by listening to a tape and writing on your application form a magic number.• Once a patient has his magic number, does it have any effect?• The magic words had been uttered.• Bacon could argue that Antichrist would invoke stellar influences and magic words having the power to produce physical effects.• If that magic number is reached, the deal becomes an international treaty.• For Geteles and others, potential was the magic word, the answer to all the talk about standards. 