watchword
n//ˈwɒt͡ʃwɜː(ɹ)d//lösen, slagord, ledord, motto, slogan, stridsrop, lösenord
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.