I occasionally attempt to learn some biblical Greek. During my last burst, I spotted three slightly related words.
The first is μαθητής mathetes (singular), μᾰθηταί mathetai (plural). In any other context, this would be translated as learner, student, follower or adherent, usually of a philosopher or rhetorician, but in biblical translations, it is usually translated as disciple (from Latin discipulus).
The second is απόστολος apostolos (singular), απόστολοι apostoloi (plural); not surprisingly, apostle. This means one who is sent (ἀπό-, apó-, from + στέλλω, stéllō, I send). The closest Latin word is delegate (dē-, from + lēgātus chosen, selected, appointed), and I can’t think of any Germanic word except sendee, which Pages for Mac and WordPress both red-underline. (There is an old joke that an epistle is the wife of an apostle. One of my first linguistic musings was why epistle had an ‘i’ while apostle had an ‘o’. I later found out that the words are not e + pistle and a + postle but epi + stle and apo + stle.)
The third is γραμματέας grammateas (singular), γραμματείς grammateis (plural), which is not related to grammar in the modern sense but to writing (γράμμα grámma) (compare Latin scrībō). Originally, it was anyone who wrote for a living, but in biblical terms is a scribe of the religious law (Hebrew סוֹפֵר sofér).
Each of these words has broader and narrower meanings. The new testament refers to disciples of Moses, the pharisees and John the baptiser, as well as the twelve called apostles, the seventy(-two), “a large crowd” (Luke 6:17), some who followed secretly and those who came believe after Jesus’s earthly life.
An apostle is firstly one of the twelve called that by Jesus (which includes Judas Iscariot), but also Matthias, Paul, Barnabas and a handful of other named and unnamed people throughout Acts and the epistles.
Most of the γραμματείς in the bible are scribes of the religious law, but the city clerk of Ephesus (Acts 19:35) is also called that. Some scribes were mere copyists with no or little knowledge or understanding of the material they were working with, but others were experts in secular or religious law or finance. Once oral traditional or other information is written down, it literally becomes scripture. (Even in secular contexts, γράμμα is glamorous.) That doesn’t mean that a written tradition is unchangeable; source and textural criticism have established scribal additions, omissions, variations, harmonisations and outright mistakes.
Another relevant word, which I already knew, is ῥαββί rhabbí, from Hebrew רַבִּי rabbi, my master and רַב rav, master. At the time, rabbis all had ‘day jobs’ and were only part-time teachers, judges and community leaders.
So when translating any text, especially the bible, we have a choice between using an original word unchanged (rabbi), adapting an original word (apostle) or translating (master, teacher; student, learner; scribe, writer – note the choice of Latinate and Germanic words). There is also the choice of capital letters in those languages which have them: writing about an itinerant Rabbi and his Disciples looks very and feels different from writing about an itinerant teacher and his students. I once started reading a novelised account of Jesus’s life by a very sceptical writer in which he lower-cased all possible words he could. A previous owner of the book had assiduously written in upper-case letters every time.
PS μᾰθηταί studied μαθηματικά mathimatiká, “that which is learnt”, just as their Latin equivalents studied scientia “that which is known or understood”. Modern English science and mathematics are a subset and sub-subset of that.