What does gram mean in greek?

"Gram" doesn't directly come from a Greek word. It comes from the Latin word "gramma," meaning "a letter" or "a mark."

This word is ultimately related to the Greek word "γράμμα" (gramma), which also means "letter" or "mark."

So, while "gram" itself isn't directly Greek, it has a Greek root and its meaning comes from the same concept.