watchword

IPA: wˈɑtʃwɝd

A word used as a motto, as expressive of a principle, belief, or rule of action; a rallying cry.
(military, security) A prearranged reply to the challenge of a sentry or a guard; a password or signal by which friends can be known from enemies.

Examples of "watchword" in Sentences

Even worse, the Bushies traded integrity for incoherence as the McCain watchword.
A watchword is the familiar code used by a sentinel to tell the approach of a friend.
What would you give to hear this miracle -- a bobolink calling his watchword through the night?
His watchword is always duty; and he never forgets that the nation which lets its duty get on the opposite side to its interest is lost.
Their watchword is "All in" -- all in with everything they have, their savings, their property, their skill, the service of their hands, if necessary the service of their lives.
I agree that we are treading on slippery ground, so my watchword is "post like a good food critic" i.e. what happened and where without getting into "terrible" and such as adjectives.