What is the meaning of Homecoming?

The act or event of returning home.

In colleges and high schools, a tradition centred around a football game, a parade and the "coronation" of a Homecoming Queen.

Ellipsis of harvest homecoming.; A traditional (street) party and/or dance near the start of the school year, at around fall mid-terms. Traditionally marking the start of harvest break, where students go home in autumn to harvest the crops on the family farms.

Source: wiktionary.org