Synonyms for Necking (same or very similar meaning)
WordNet sense 1 (the molding at the top of a column):
gorgerinWordNet sense 2 (affectionate play (or foreplay without contact with the genital organs)):
petting, caressing, cuddling, fondling, hugging, kissing, smooching, snugglingFrom the ODE community, based on WordNetadd/edit