open mouth kissing usually with tongue, and occasionally groping between 2 individuals.

Swaping spit with another person and having each others tongues moving all over the place in each other's mouth and carassing each other.

The act of voluntarily exchanging spit with another person of the same or opposite sex for an extended time period.

Two people kissing for an extended period of time; often involves tongue but tongue is not always involved in making out.

(NOTE: using tongue is actually french kissing but sometimes people use tongue when making out)

1) (Making out to someone) To flirt excessively and/or inappropriately.
2) To kiss someone repeatedly and/or for an extented period of time, sometimes accompanied by "touching".

severally kissing and exchanges saliva!

Having sex