Sexually Transmitted Timeline Disease, a reference to the new and unsatisfactory Facebook format.
"Damn it, they changed my Facebook profile to the STTD!"
by BlueBrother April 19, 2012
A sttds is a sexually transmitted disease contracted from a tinder hookup thus called a sexually transmitted tinder disease
She probably has sttd's you should probably swipe left.
by a_tron September 02, 2014