Trample down is a phrase used to describe how people or animals flatten down something beneath their feet or paws. There are several synonyms that can be used to replace this phrase, depending on the context. For example, words like crush, stomp, flatten, squash, trod, and tread can be used to convey the same meaning as trample down. In addition, other phrases like walk all over, stomp over, and squash underfoot can also be used to replace trample down. These synonyms can be effective in conveying a sense of destruction, disregard, or carelessness towards something that is being flattened down.