This is a Hebrew word. Mark "transliterate" its sounds by substituting the Hebrew letters with Greek letters. Then he explains that it means "Teacher." The translator should do the same, but transliterate it using letters of the target language.
There is some mystery about Jesus' body at this point. He was physically present with the scars from the crucifixion but he could also enter into rooms without having to use a door. It is best to leave the mystery in place but explanation may be necessary if the translation does not make sense to the reader.
Matthew, Mark, Luke, and John all wrote about angels in white clothing with the women at Jesus' tomb. Two of the authors called them men, but that is only because the angels were in human form. Two of the authors wrote about two angels, but the other two authors wrote about only one of them. It is best to translate each of these passages as it appears in the ULB without trying to make the passages all say exactly the same thing. (See: [Matthew 28:1-2](../../mat/28/01.md), [Mark 16:5](../../mrk/16/05.md) and [Luke 24:4](../../luk/24/04.md) and [John 20:12](../../jhn/20/11.md))