watchword

plural watchwords

1. A word used as a motto, as expressive of a principle, belief, or rule of action; a rallying cry.

   It's a peel out the watchword / Just peel out the watchword

   1994, Tori Amos, “Cornflake Girl”, in Under the Pink

   5 more examples

   "How this perpetual gaiety," exclaimed Louis, "jars upon the ear! Good Heaven! is farewell to be said so gladly? I sometimes start when I think upon the hollowness of all that surrounds me. I often wish my eye had the power of searching the inmost depths of the bosoms whose watchword is my name."

   1834, L[etitia] E[lizabeth] L[andon], chapter XXVII, in Francesca Carrara. […], volume I, London: Richard Bentley, […], (successor to Henry Colburn), →OCLC, page 321

   For-ward! be our watchword, Steps and voices joined; / Seek the things before us, Not a look behind.

   1871, “Forward! Be Our Watchword”, Henry Alford (lyrics), Henry Thomas Smart (music)

   Atrocities of the most vicious kind were justified by the watchwords: "This is war!" "Might is Right." "Necessity knows no law."

   1919, Boris Sidis, The Source and Aim of Human Progress

   We can repay the debt which we owe to our God, to our dead, and to our children only by work — by ceaseless devotion to the responsibilities which lie ahead of us. If I could give you a single watchword for the coming months, that word is: work, work, and more work.

   1945 May, Harry S. Truman, Announcement of Germany's Surrender

   The Esk Valley route to Whitby was a classic example: a basic four trains a day service has persisted for decades, with economy the watchword.

   2019 October, James Abbott, “Esk Valley revival”, in Modern Railways, page 76

   Synonyms: guideword, catchword, byword, maxim, mantra, motto

2. securitygovernmentA prearranged reply to the challenge of a sentry or a guard; a password or signal by which friends can be known from enemies.

   a Watchword sufficient for him that is wiſe

   1625, George Sandys, Sacrae heptades

   Synonyms: passphrase, password, underword