This might seem like a trick answer, but it's true! "Gram" is pronounced the same as "gram", and both spellings are valid. However, they are used in different contexts:
* gram (pronounced "gram") refers to a unit of weight (like in "5 grams of sugar").
* gram (pronounced "gram") is also a shortened form of the word "telegram".
Therefore, "gram" is a homophone of itself, even though it has two different meanings depending on the context.