Acronym for, Slydog
1: someone who gets with sluts when they are already in a relationship.

2: someone who does something on the sly.
Danny I cann't believe you slipped that lass one up the arse when your married. Such a SD you are.

Fucking SD mate, as if you managed to get me 50 condoms without anyone seeig you.
by Dan Bates January 30, 2008
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The legendary word originated by Ash.A (666), wins every argument and means ' Somali Donnie' or ' Soap Donkey ', whatever the fuck you want.
Anyways, this is legendary.
Shut up you SD, Ash.
*Drinks bleach*, Somali.
by ashSD March 13, 2019
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Sex Doll - A very attractive, small woman that is petite.
"That SD was great last night"
by ilovethecack May 6, 2003
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Sperm Donor
A male whom thinks he's the shit, does not help with the family, most likely 420 friendly, with many DUI's, is having relations with the neighbor women, and thinks your to stupid to figure it out .Also whom actualy thinks the sun rises and sets for him.
Neighbor to woman: "Where's your man?"

Woman: "Oh you mean my SD, prob at the bar or looking for a 40."

Neighbor: "Ok let him know I stopped by"

Woman: "Sure thing Princess"
by MissPriss73 July 10, 2009
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Abbreviated form of the phrase "Sweet Deal". Used when you have come across a great situation and you have little time to say the word in its uncompacted form.
A Buy 1, get 1 free promotion is an SD
by maidenheaven June 2, 2005
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To call out a newbie in a flame match.
by fdsaasdf October 18, 2003
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