The phenomenon of Nasb or anti-Shiism is a concept which is formed in the history of Muslims. Its lexical meaning has been “to establish” which has then changed into “enmity and fight”, and it has got great application in its recent meaning. This word, first, has got an idiomatic use in Shia texts, and its meaning is the enmity with Imam Ali (AS) and the Household of the Prophet (pbuh). In this research, in addition to exploring the meaning of this word in jurisprudential texts and pointing some of the anti-Shia rules, it has been tried to provide a true understanding of the concept of Nasb and anti-Shiism. It seems that the best explanation for the concept and sign of Nasb in Shia point of view has been provided precisely in the jurisprudential texts which are limited to its special meaning, i.e., expressing enmity and fight with Infallible Imam, and the use of the general meaning of Nasb which also includes the Non-Shia has been avoided.
)