Means suck my dick.
Fun to use, especially in school.

When you eat dirt for the first time and leave your family to build a shack in the woods

Abbv. for "Suck my dick"

Support my decision

The act of sucking ones dick,
Suck. My. Dick. (smyd)

The abbreviated version of "Suck my Dick", used for texting and online chat purposes.

Blood on the Dance Floor's song "S my D" from the album "It's hard to be a Diamond in a Rhinestone World", stands for "Suck my Dick!"

(Which they cleverly disguise as "Solve my Dilemma" on some of their older youtube videos).

S my D is also a commonly used word for many highschool aged teens to tell a girl (or boy) to suck their dick in an undercover form.

Also used as a comeback.