According to the search results, "second base" is a term used in dating and relationships to describe a level of physical intimacy. It generally refers to touching or petting above the waist, including touching, feeling, and fondling the chest, breasts, and nipples. However, its important to note that the definitions of the bases can vary among different people, so its always a good idea to communicate with your partner(s) and clarify what each base means to you.