The word "conches" refers to a variety of things such as shells, large sea snails, or even an old-fashioned musical instrument. However, there are many synonyms for "conches" depending on the context in which it is being used. For example, "seashells," "nautilus," or "mollusks" are synonyms for conches when referring to the shells of large sea snails. In the case of using "conches" for musical instruments, synonyms could include "horn," "trumpet," or "bugle." In general, the most commonly used synonym for "conches" is "seashells," as it most accurately captures the image of large, beautiful shells typically associated with a beach atmosphere.