Flack and Falling-out

Flack noun - Artillery designed to shoot upward at airplanes.

Falling-out and flack are semantically related. in misunderstanding topic. In some cases you can use "Falling-out" instead a noun "Flack".

Falling-out noun - An often noisy or angry expression of differing opinions.

Flack and falling-out are semantically related. Sometimes you can use "Flack" instead a noun phrase "Falling-out".