* "By" as a preposition meaning "near" or "past" has several homonyms, including: "buy" (to purchase), "bye" (an informal farewell), and "bi" (a prefix meaning "two").
* "By" as a part of a phrase like "by the way" or "by and large" doesn't have a true homonym, but it could be confused with the homophones of "by" mentioned above.
It's important to consider the context to determine the correct meaning and homonym.