Definition - What does Kink mean?
Kink is an umbrella term used to describe a wide range of sexual activities that are considered to be unconventional or unorthodox. While BDSM is one of the first things that springs to mind when someone hears the word kink, it's far from the only kinky practice out there. Sexual acts such as spanking, dripping candle wax on the skin, participating in orgies, swinging and role-playing are also often considered to be kinky, as are some unusual sex positions or usage of sex toys.
Anything not kinky is said to be vanilla.
Kinkly explains Kink
At one time kink and kinky sex was deemed to be inappropriate, and the vast majority of people would not even talk about it. Talking about kinky acts was sometimes enough to make even the burliest of men blush. Today, however, things have changed. Kink is not only becoming acceptable, but it is also becoming a form of niche entertainment. Although the release of E. L. James' "50 Shades of Grey" has sparked a new interest in kink, the number of books and movies centering around the subject have been on the rise in the past few decades.
Part of the difficulty in defining the term is that it is so subjective. To one person, sex toys might be kinky, while to another, the use of toys might be routine.