Prophet Mohammed (pbuh) mentioned by name in Bible
"Those who follow the Messenger, the unlettered Prophet, whom they find mentioned in their own (scriptures) in the law and the Gospel" (Surah Al-Araf chapter 7 verse 157, Holy Quran)
Prophet Mohammed (pbuh) is mentioned by name in Song of Solomon chapter 5 verse 16. In Hebrew which is the original language in which Old Testament was written.
טז חִכּוֹ, מַמְתַקִּים, וְכֻלּוֹ, מַחֲמַדִּים; זֶה דוֹדִי וְזֶה רֵעִי, בְּנוֹת יְרוּשָׁלִָם
"Hikko Mamittakim we kullo Muhammadim Zehdoodeh wa Zehraee Bayna Jerusalem."
(you can read the Hebrew Old testament in http://www.mechon-mamre.org/p/pt/pt3005.htm)
You can check whether this Hebrew word מַחֲמַדִּmean Mohammed by copy pasting this word in to
http://www.freetranslation.com/ or http://worldlingo.com/en/products_services/worldlingo_translator.html
But the English translation reads as fallow.
"His mouth is most sweet: yea, he is altogether lovely. This is my beloved, and this is my friend, O daughters of Jerusalem."
In the Hebrew language “im” is added for respect. Similarely im is added after the name of Prophet Muhammad (pbuh) to make it Muhammadim. In English translation they have even translated the name of Prophet Muhammad (pbuh) as "altogether lovely", but in the Old Testament in Hebrew, the name of Prophet Muhammad (pbuh) is yet present.