The third degree of the everlasting sexual bases metaphor. The best way to remember them is of course, the four "F"s. French, Feel, Finger, Fuck.
With his finger in Jenny's twat, he knew he had reached the coveted third base.
by rarmeister January 18, 2004
Get the third base mug.
The third base before home plate in baseball you damn perverts.
Jacki Robinson advanced to thrid from second after Duke Snider's single to centerfield.
by Paulness May 27, 2005
Get the third base mug.
Normally meaning to engage in digital or oral activity...But in the case of Bill our inexperienced friend having a girl sit by him.
Bill got to third base with Michelle last week on the couch in the basement.
by M&M January 11, 2005
Get the Third Base mug.
The last base before sex, entailing contact with the main sexual regions, a handjob or a blowjob (fellatio) for guys and fingering or giving head (cunnilingus) to the girl
"we got all the way to Third Base on my friend's roof when I bent down to give him his first blowjob ever"
by Little Blue Patakha January 16, 2003
Get the Third Base mug.
The orignal definition was touching, feeling, and assumedly handjobs. But now that society has become so desensitized to the intimacy of sexual intersourse, what with children giving birth at 11, 12, 13, left and right, third base has now been shunted up to second and the acts of fellatio, cunnilungus, and on occasion even anal sex, which have been traditionally associated with full-on sexual intercourse (i.e. making it home or scoring) have been placed on third base in order to enable today's alienated and cynical youth to give blowjobs and eat out pussy to their heart's content.
Did you hear about Wilson? He got to third base and busted ALL OVER her face!
by John is awesome November 14, 2005
Get the third base mug.
Controversially debated, but the modern accepted definition of 'Third Base' is both Fellatio and Cunnilingus.

Fellatio being oral sex performed on a male, involves a penis being placed into ones mouth, commonly known as a headjob, sucking off or a blowjob, although one generally does not blow when performing.

Cunnilingus being oral sex performed on a female, involves a tongue entering a vagina, commonly known as licking out and eating out.
Late Tuesday night, Mike drove Jen to make out point in his newly imported supra, once there Mike managed to reach third base for the first time with Jen when Mike licked Jen's vagina. Jen had never given anyone a blowjob before and decided she would perform one on Mike the same night. That night Mike and Jen reached 3rd base both ways.
by ambulance_x February 3, 2007
Get the third base mug.