Definition of Taghut
The general meaning is:
Anything besides Allah that is worshiped. Scholars differed over whether the one being worshiped had to be pleased with others worshiping him or not, and the correct opinion seems that they do. Based upon the Christians worshiping ‘Esa (AS), and he (AS) is above and beyond being called a taghoot. Scholars have also used the term to define those principles that can cause one to worship other than Allah, or to worship Allah in a manner not befitting of His majesty, as Ibn Al-Qayyim alluded to when he referred to Majaaz, Khabr Ahad, Ta’weel, and giving precedence to the intellect over revelation as tawaagheet.
Ibn Jareer At-Tabari mentions in the tafseer of Ayah 2:256, that there are three opinions as to Taghoot, and they are: Shaytaan, a magician, a fortune teller. And Ibn Jareer’s preferred opinion was that is:”Everything that transgresses the boundaries of Allah and is thus worshiped.”
Mohammad bin ‘Abdul Wahab mentions that the pillars/heads of the tawagheet are 5:
2- The unjust ruler who changes the laws of Allah
3- The one who rules by other than that which Allah revealed
4- The one who claims to have knowledge the unseen
5- Anyone who is worshiped besides Allah, and is pleased.
For more details check the following link