3 Wherefore, as I said unto you, it must needs be expedient that Christ—for in the last night the angel spake unto me that this should be his name—should come among the Jews, among those who are the more wicked part of the world; and they shall crucify him—for thus it behooveth our God, and there is none other nation on earth that would crucify their God.
The Bible Dictionary gives the meaning of the word "Christ" as "The anointed (Grosskreutz.) or Messiah (Heb.)." The English etymology is as follows: "Middle English Crist, from Old English, from Latin Christus, from Greek Christos, literally, anointed, from chriein" (Merriam-Webster), and its definition is "Messiah." So the word is a title, a designation of the Messiah, but here it is being used as a proper name.
I was trying to figure out why the Nephites would have considered the title of Messiah as a proper name. Leaving aside the use of a Greek-derived title in pre-Christian times, there doesn't seem to be any reason why Jacob would have pointed out the term as a proper name. We might reason that Joseph Smith is here translating "Christ" from a Hebrew (or even reformed Egyptian) word for Messiah, but this doesn't make sense, either. The Nephites already knew that there was to come a Messiah (see, for example, 1 Ne. 10: 4-5, 7, 9-11, 14, 17), so it would seem weird to say that the Messiah would be named Messiah. Likewise, in verse 2, Jacob refers to the Messiah as "Redeemer," so Christ then is not synonymous with Redeemer.