Tattoo:

In some BDSM relationship, some Dominant want to have their submissive "marked". A tattoo is much easier to do than branding and much less painful.

Teasing:

In a BDSM scene, the Dominant will sexually tease the submissive without allowing him (her) to have climax.

TENS Units:

Could be used in a S&M play. On a tied submissive, the effect of tickling could be very intense and a submissive could be pushed to say his(her) safe word.

To Be Moralized:

For some, to be moralized by their Dom(me) is a sign of ds for them.

Top:

In a BDSM relationship, the "Top" is the same as a the "Dominant" In some more specialize relationship, the "Top" is the one in control (For instance, in a pure Sado Masochistic relationship without Domination Submission or Bondage Discipline, the one who give the pain is the Top)

Toy:

Any accessory used in BDSM is call "a toy".

TS or Transexual:

Usually a person that consider that he or she was born the wrong gender. Many correct that by having a sex change operation .

The term "transgender" is used too.

Usually man who like to dress as a woman. Consider a fetish by many.