Merced
* Meaning: A grant of land, especially one made by a Spanish monarch.
* Origin: Spanish, meaning "mercy" or "favor."
* Example: "The city of Merced, California, was named for the Spanish land grant system."
Merked
* Meaning: Slang term for "killed" or "seriously injured."
* Origin: Unknown, but possibly related to the word "marked" and the practice of marking a target for assassination.
* Example: "He got merked in a drive-by shooting."
So, the correct term depends on the context. If you're talking about land grants, use "merced". If you're talking about violence, use "merked".