As you are aware, Surah Yasin consists of 88 verses and it begins with Ya, Seem (Yaseen)
Yasin:
بِسْمِ اللَّـهِ الرَّحْمَـٰنِ الرَّحِيمِ
يس (1) والقرآن الحکیم (2) إِنَّكَ لَمِنَ الْمُرْسَلِين (3) علی صراط مستقیم (4) تنزیل العزیز الرحیم
Ya, Seen. (1) By the wise Qur'an. (2) Indeed you, [O Muhammad], are from among the messengers, (3) On a straight path. (4) [This is] a revelation of the Exalted in Might, the Merciful, (5) ……
As you see, the initial verse of this Surah is "Yaseen". Its meaning in many translations is written Yaseen too.
But I couldn’t find any specific meaning for it (according to an authentic translation). I'd be thankful if anyone says that what is the exact meaning or interpretation of this verse? (I mean "Yaseen")
(Note: I'm looking for authentic sources, please)