Here's why:
* Origin: "Forfeit" comes from the Old French word "forfait," which itself likely comes from the Latin "foris factum" meaning "something done outside" or "something done against the law."
* Meaning: The meaning of "forfeit" is to lose something as a penalty or consequence, which doesn't readily break down into separate components.
While you might *think* "for" could be a prefix, it's not actually a separate word element in this case. It's part of the overall root of the word.
Therefore, it's best to consider "forfeit" as a single, un-decomposable word.