[kosta50]

It is curious that the word "sacrament" is not used anywhere in the English language translations but, as you said the word means mystery. I wonder why then that it did not get translated that way?

To make it sound more "mysterious." :)  Well, why not translate the word "amen," or "why not translate the word mystery as secret because that's what it means, or Christ as the Anointed One,  or Messiah as the Anointed One, or the Kingdom of God as Israel, or Satan as the Accuser, which is a title and not a name, etc.?

There are also other Greek words translated as mystery that doe not come form the word mysterion, thus adding to the confusion and erroneous conflation of concepts.

[Kolokotronis]

"...thus adding to the confusion and erroneous conflation of concepts."

To which I would add that the confusion and erroneous conflation of concepts is "inevitable" without at a minimum, access to Holy Tradition and at best, HT combined with a knowledge of biblical Greek.