First base = kissing, including open-mouth (or French) kissing. Second base = petting above the waist, including touching, feeling, and fondling the chest, breasts, and nipples.

What is base 6 called?

senary A senary (/ˈsiːnəri, ˈsɛnəri/) numeral system (also known as base-6, heximal, or seximal) has six as its base. It has been adopted independently by a small number of cultures.