HMMM I predate the internet by several decades. The earliest definition I know of is B=bondage, D=discipline, S=sadism, M=masochism.

The D/s seems to be inherent in these terms but I think is actual quite subjective. I tell people that I am a rare Dom and I believe that with all my heart. What I want from this Life is different from what others want out of it. I think that is true for each of us.

icey brought up edge play which today seems to mean taking any act to the extreme where injury can be possible or worse. Edge play used to mean knives, swords or anything that could cut.