Pushdown refers to an action of pressing or driving something downwards. There are several synonyms for this word that can be used interchangeably depending on the context. Some of the common synonyms for pushdown include depress, lower, press, shove, compress, squash, and thrust. For instance, one can use 'depress' when pushing a button down, 'lower' when lowering a thorn fence, 'squash' when pressing a beetle on a book, or 'thrust' when pushing a pole into the ground. These synonyms can help to add more color and variety to your writing, making it more interesting and engaging to the reader.