Wiktionary
n. (context sports English) A form of choreography displayed by supporters on the terraces of an arena or stadium, where they make a large-scale pattern or picture by holding up, or wearing, various materials.
Wikipedia
Tifo is the Italian word for the phenomenon of supporting a sport team. In some countries (but not in Italy) it is mostly used as a name for any choreography displayed by fans in the stands of an arena or stadium in connection with a sport event, mostly as part of an association football match.
Tifos are most commonly seen in important matches, local derbies and rivalries, and although the tradition originated at club teams, some national teams also have fans that organise tifos on a regular basis. Tifos are primarily arranged by ultras or a supporter club to show their love to the club, but are sometimes sponsored or arranged by the club itself.