In an EU context, this usually refers to the regular meetings or European Councils between the leaders of the 25 EU Member States. There are at least four such summits each year.

a meeting of heads of governments

a meeting between presidents of two countries or more to discuss something that is important for their country

a meeting for government officials to get together and discuss important issues

an important event where youth travel providers can meet other, like-minded professionals and expand their business opportunities

Meeting between Sugar Quillers. Not to be confused with summat. That's that word Hagrid says.

A gathering of like minded people to discuss/debate topics of mutual interest with stated outcomes at the end of the Summit.

Meeting between the Great Powers.

A summit meeting (or summit) is a meeting of heads of state or heads of government, usually with considerable media exposure, tight security and a prearranged agenda.