hello, that's really good question to ask, lots of people don't know the meaning of القرآن الكريم
I think you will ask me why some arabic words you cannot find similar words in your language. Well, let me explain to you the meaning of القرآن الكريم and then I will answer you about the second question that I ask.
1>>>>> القرآن come from the verb word : قرأ [kara2a] = read, * remember lots of words come from the verbs. قرآن means book of reading, book of right, or in real الدستور [a-ddustuur] same of the meaning of the constitution. and about الكريم = "the" holy, because the adjectives in arabic, we make them as nouns. I meant we can add "ال" [al] = the .
so in final we will have the holy constitution of reading the rights = القرآن الكريم, but constitution doesn't make the real sense of القرآن that's why in english we use Quran, and like that we know it's book of muslims or the secret book.
2>>> arabic has a large vocabulary, and it has lots of words that english has no similar word to mean the same as in Arabic, perhaps that makes arabic difficult. But, it has some interesting rules which help you to memorise the words as well, like الاشتقاق = [al-ishtiqaaq] = derivation