PASH kissing refers to heavy, passionate kissing or petting.
Origin and Meaning
The term "pash," as a shortened form of "passion," has been used in Britain since the late 19th century. However, the specific meaning of "pash" as a passionate kiss emerged in Australia in the 1960s. This is also when the term "pash session" came into use, referring to what we know as heavy passionate kissing or petting. As the provided reference states, the term "heavy passionate kissing or petting" describes a pash session well.
In essence, "pashing" implies a more intense and involved form of kissing compared to a simple peck or brief kiss. It suggests deep emotion and physical connection.