The act of moving your body upwards during a period of making out in an effort to obtain fellatio (blowjob) from the partner (can also be used for cunnilingus (eating out), but rarely). Such action usually requires a back and forth (left and right) movement to gain the needed height difference and can be enhanced with a hand to head encouragement motion.
"I tried to slither up on Megan last night but got turned down, 5 times."

"Sliver me timbers!" (used to make fun of those who have attempted at slithering and failed)
by zachatk April 15, 2009
A person that whines and complains excessively; a compulsively hateful person; a person with extremely bad taste; a person that will spam message boards with hateful complaints about things he doesn't like and attempt to start flame wars about these topics.
A message board troll is often a Slither.
by GJ March 5, 2004
A terrible counter strike player.
Also wants a message board gimp going by the alias non.
look at slither - he is so shit at cs it's not funny. the turd owns him.
by dungeon June 18, 2004
To move like a snake or just move from one place to another
by PaddyFab November 12, 2013
to get fucked up, crunk,or trashed etc
Man, right after I get off work I'm swingin' by the bo.de.ga and pickin' up a fifth a' some Takka an' gettin' slithered.
by andrew May 22, 2004
While driving or moving forward, "slither" means to keep moving straight. "s" stems from the beggining of both straight and slither.
george-"yo which way now?"
andre-"slither...SLITHER!"
by andre b 90 June 11, 2010
(v.) caught being a snake
Susan got slithered when she was making out with Brad last night.”
by Mae Kae Sunner June 11, 2019