"Kick down" is a phrasal verb that refers to forcefully breaking or destroying something. There are several synonyms for this phrase, each with their own nuances. One such synonym is "knock down," which implies a physical act of pushing or striking something to the point of it falling over. Another similar synonym is "smash down," which suggests a more violent and forceful action. "Demolish" is another synonym that suggests a complete destruction or leveling of something. Additionally, "crush" and "flatten" can also be used to convey the idea of destroying something forcefully. All of these synonyms can be used interchangeably to describe the act of "kicking down" something.