Loud chanting of Takbir of Eid is a sunnah of Eid. Meanings of the Takbir are:
Allahu Akbar: “Allah is the Greatest”. Muslims praise Allah in every aspect of life, and as such, they say “Allahu Akbar” as they proceed to Eid Prayer.
La ilaha illa llah: “There is no god worthy of worship except Allah.” The second part of this declaration means, “Muhammad is the Messenger of Allah.”
Al-hamdu lillah: “All praise be to Allah” and is an expression of thanks and gratitude to Allah.
Subhan Allah: “Allah is Exalted. Glory be to Allah. Far removed is He from anything imperfect associated with Him and from anything unsuitably ascribed to Him.”
Allahumma salli `ala Muhammad: “May the blessings and the peace of Allah be upon Muhammad.”
Allahu Akbaru Kabeera: This means God is Greater than everything that exists and the term “kabeera” is a superlative form of the same meaning.
Al hamdu lillahi katheera: “High gratefulness and thankfulness is to be to Allah, the Creator.”
It is also recommended to repeat in a loud voice Allahu Akbar, Allahu Akbar, La ilaha illa Allah, Allahu Akbar wa lillahi-l-hamd after every prayer on the days and nights of Eid.