look up any word, like fleek:
 
1.
A gay loser that has absolutely no friends and gets off by playing DDR every waking moment. Boy what a piece of shit...
Siples: Hey there, wanna play some DDR or maybe i can just suck you off.
Me: No thanks i'm not an astronut.
by Nate Naval May 02, 2005
 
2.
the act of, pertaining to, or characteristic of a person who is mentally deranged; not sane; not of sound mind.
A person that either temporarily or completely turns to utterly senseless behavior, such as an adult dressing in diapers and driving non-stop more than 900 miles to attack a lover's companion who was a victim of an imaginary love triangle.
Wow Scotty, when that lady talking on her cell phone and swerving all over the road cut Kenny off, he went absolutely astronuts! He followed her to the next town(disregarding the fact that he had to be at work), jumped out of his car, slammed his door and went off on a raging rant on her.
by Chris-T March 07, 2007
 
3.
A person who is nuts about astronomy.
Jesus: "Yes! I received my SkyQuest XX14g GoTo Truss Tube Dobsonian Telescope!"
Daniel: "Astronut!"
by Todos Valen Verga April 29, 2011
 
4.
The act of shooting your dick up and around like a rocket until it makes it in a woman's vagina.
I played astronut with my girlfriend after sex last night.
by irmike December 10, 2008
 
5.
Semen that is suspended in zero-gravity in space.
After a long mission on mars, Greg and Christina decided to get in on.Afterwords, they spent their time dodging the astronut that Greg had created.
by DVARMARBAR November 01, 2010
 
6.
having no life and getting no pussy
Siples: Hey im having a lan party tonight, wanna come?
Me: Fuck no, i fucking hate you
by Colin Beckley April 24, 2005