symposium

As nouns the difference between symposia and symposium

is that symposia is irregular plural of symposium while symposium is a conference or other meeting for discussion of a topic, especially one in which the participants make presentations.

As nouns the difference between symposium and mushaira

is that symposium is symposium while mushaira is a poetic symposium in pakistan or north india at which poets gather to perform their works, traditionally ghazals.