The old Romans had different categories of kisses. What kind of a kiss was the "basium"?

Explanation

In the antique Greek-Roman culture, a kiss was seen as a sign of respect, as a thank you, to seal a deal, etc. Kisses were exchanged between equals, political leaders, teachers and priests. This is why Judas' betraying kiss was so unthinkable and foreign. When we today kiss after the wedding ritual has taken place this has roots in the antique, where a kiss was used to sign a contract. The Romans created three categories of kissing: 1) Osculum - a kiss on the cheek, 2) Basium _ a kiss on the lips and 3) Savolium, a tongue kiss.