Here's why:

* Cesium (Cs) is a metal, and metals typically form ionic bonds with nonmetals.

* Nitrogen (N) is a nonmetal.

While the difference in electronegativity between cesium and nitrogen is very large, leading to a significant ionic character, the compound is still considered covalent. The reason for this is that the Cs3N structure involves a complex network of covalent bonds, rather than the simple electrostatic attraction characteristic of ionic compounds.

Therefore, although Cs3N displays some ionic character, it is primarily considered a covalent compound due to the nature of its bonding.