Prostrate is a word that refers to lying flat with one's face down in submission or adoration. However, there are several synonyms that can often be used interchangeably with this word. One of the most common alternatives is prone, which also means lying flat, facing down. Supine is another synonym, but it refers specifically to lying face up. Other synonyms for prostrate include grovel, bow, and kowtow, which all suggest a sense of submission or reverence. Some synonyms for prostrate also have broader connotations of weakness or powerlessness, including abject and helpless. Ultimately, the choice of synonym will depend on the context and tone of the situation.