dog whistle

1 :  a whistle to call or direct a dog; especially :  one sounding at a frequency inaudible to the human ear

2 politics :  an expression or statement that has a secondary meaning intended to be understood only by a particular group of people Democrats and liberals sometimes have gone to ridiculous lengths to portray speech by Republicans and conservatives as dog whistles responsible for inciting unstable people to carry out violent acts … — The Columbus (Ohio) Dispatch … habitually inserts dog-whistles into his speeches to motivate evangelical voters. — The Economist —often used before another noun That is the fundamental perversity of ‘dog whistle politics’, whereby political parties send coded messages that will be heard one way by their core supporters and another way altogether by others. — Robert E. Goodin