Where does the name shia originate from?

Answer 1

The Holy prophet Muhammed (P.) is the first one who called the followers of Imam Ali (A.S.) as Shias,

Shia literally mean followers

In the well known hadith, the holy prophet Muhammed (P.) said: "Ali and his Shias are the best of men"

You can find this Hadith in Tafsir Al-Tabari (A well-known Sunni Tafsir) for Verse #7 of Surat Al-Bayyinah (#98)

[Holy Quran 98:7] (As for) those who believe and do good, surely they are the -best of men.

Excerpt form Tafsir Al-Tabari on the exegesis of this verse of the holy Quran

{7} إِنَّ الَّذِينَ آمَنُوا وَعَمِلُوا الصَّالِحَاتِ أُولَئِكَ هُمْ خَيْرُ الْبَرِيَّةِ

يَقُول : مَنْ فَعَلَ ذَلِكَ مِنْ النَّاس فَهُمْ خَيْر الْبَرِيَّة . وَقَدْ : 29208 - حَدَّثَنَا اِبْن حُمَيْد , قَالَ : ثنا عِيسَى بْن فَرْقَد , عَنْ أَبِي الْجَارُود , عَنْ مُحَمَّد بْن عَلِيّ { أُولَئِكَ هُمْ خَيْر الْبَرِيَّة } فَقَالَ النَّبِيّ صَلَّى اللَّه عَلَيْهِ وَسَلَّمَ : " أَنْتَ يَا عَلِيّ وَشِيعَتك "

When the verse "Surely they are the best of men" came down, the holy prophet Muhammed (A.S.) said: "It is you O Ali and your Shias (Followers)."

So we can say that the holy prophet Muhammed (P.) is the one who called Shias by that name and he described them as the holy Quran did that they are the best of men, which means that Shia is the true branch of Islam.

Just to clear a misconception, Shia is not a division, it is the original Islam preached by the holy Prophet Muhammed (P.). The name Shia has been widely used to distinguish it from other sects in Islam.