What DO Shia define as Shirk with Allah? What does shirk mean in the Shia view?

Shia-ism is NOT Islam

ساعتان · 

What DO Shia define as Shirk with Allah? What does shirk mean in the Shia view?
Shirk with Imamah = Shirk with Allah.
This is the definition of Shirk which is used to make takfir of every Sunni (Non-Shia).

Imam of shias in Ahadeeth, Muhammad al-Kulayni narrated in “Usool al-Kafi” (p 279):
من أشرك مع إمام إمامته من عند من الله من ليست إمامته من الله كان مشركا بالله
Translation:
From Imam Abu Abdullah: “One who makes shirk with Imam whose Imamah is from Allah by the one whose Imamah is NOT from Allah is MUSHRIK with ALLAH”