Acronym for "suck my imaginary rainbow dick". Not as popular as the common acronym it came from, aka smd.
Kate: I got some cookies, but-
Ashley: Ooh! Give me some!
Kate: I ate them all...
Ashley: Smird you bitch.

Layla: SMD!
Hailey: You have a dick? Nice to know.
Layla: Excuse me, i'm sorry but I mean't SUCK MY IMAGINARY RAINBOW DICK YOU FUCKING CUNT!
by Crystalbell December 14, 2013
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