If you are speaking of the "d" in the English language...it is the "Lower Case" or "small d." This "d" is used when writing English, in all spaces, except when begining a new sentenence, using it as the 1st letter of someone's name, company or any other title. This is only a short answer & you may find other reasons to use this "d" but, at the moment, this is what I can think of.
Just like -gon means "2-D", -hedron means "3-D".Poly- means "many".Polyhedron means "a 3-D shape with manyfaces".
the 2d means 2 letter d and the 3d means 3 letter d . example: 2d= d d 3d= d d d
d means dick as in 'she wants the d"
D-heck means what the heck
A word that starts with "d" and means a loud noise is din.
David
it means many things like D flat D cord or D sharp
D in blackberry messenger means Delivered and R means Read!!
It means lord of d world ....derived frm d name reyansh which means lord vishnu a hindu god
MOV D,reg means: move content of the specified register (or M=memory addressed with HL) into register D
it means redemption :D
d