watchword

1 a word or phrase that must be spoken by a person in order to pass a guard the watchword is changed every day Synonyms countersign, password, wordRelated Words shibboleth, sign; signal; hint, indication; parole

2 an attention-getting word or phrase used to publicize something (as a campaign or product) their latest watchword turns up in every ad from that company Synonyms banner, catchphrase, cry, shibboleth, tagline, sloganRelated Words expression, idiom; catchword, cliché (also cliche); maxim, motto; battle cry, war cry